Abbott Freestyle Navigator

I've had an Abbott Freestyle Navigator for 6 months now. I love it, most of the time. I have both hypo glycimic unawareness and hyper glycimic unawareness. I've been a Type 1 diabetic for 31 years and on an insulin pump for 10 year.

Pros

*Constant readings with arrows to show if stable, rising, or decreasing.
*After 2nd calibration readings are generally just within 3 points of regular blood test. Although, I still do regular blood test if low or high readings occur.

Cons

*If batteries run out have to remove sensor and change batteries. I usually change batteries if less then 75% of battery life shows as I had issue with a few bad batteries. :)Abbott Freestyle now sends 2 batteries per box of sensors and have not had to buy these batteries on my own even with my over changing batteries.
*If dehydrated sensor readings are inaccurate so drink water. I live in Nevada and didn't realize how frequently I was dyhydrated. I now drink water constantly.

Pros

It alerts you for upcoming low and high glucose levels. (up to 30 min.) It's light weight and can be worn up to 5 days. Works even when taking a shower or swiming.

Cons

I am very active and I sometimes have to wear a extra adhesive pad over the sensor. I just use the clear iv adhesives.

Pros

The Freestyle Navigator by Abbott

First off, I'll suggest you to follow this link to Abbott's website, for an excellent description of the Navigator, and a simulator that lets you try out all the buttons on the receiver.

http://www.freestylenavigator.com/ab_nav/

My Navigator Pictures:
http://www.diabetesdaily.com/forum/m…u...

Initial Setup

Abbott does not sell the navigator itself, it has a number of distributors. I got mine from Smith's medical, as they are offering a large discount on it to their customers. The ordering process went very smoothly, I downloaded the necessary forms in pdf format, filled out my part and dropped the forms off at my doctors office. A few days later the Navigator was shipped.

Due to my remote location, and my experience level, I decided to skip having a trainer come here. I read the manual online ahead of time, and tried out the simulator online, which told me tons of things. It's really good, I found no differences at all between how the simulator works and the real thing, as far as how to use it.

Due to the cost of sensors, I did decide to give a call to tech support when I was ready to insert sensors, so they could double check me to make sure I did not miss a step or something else equally dumb.

The call to tech support was answered promptly, I gave them my info and status. The lady answering the phone was not fully trained, and said so, and said there were 2 qualified people there and both were helping people and I would get a call back in 15 minutes. I got a call in about 5 minutes. This is a new product, they are still ramping up, I was very satisfied with this.
I had installed the batteries and set the clock. I elected to put the sensor in my left arm. I found this to be a bit awkward, but with the aid of a mirror on the wall it went ok. A little bit of bleeding, but that stopped rapidly. Did it hurt? Much less than a fingerstick .

After installing the sensor, and putting the transmitter on the mount that holds the transmitter and sensor, the transmitter and receiver started talking to each other in a couple of minutes. This meant I was done until calibration time, about 10 hours later.
Calibration is not on a 10 hour timer, but rather, the navigator keeps testing and looking at the results until it is really stable, which takes about 10 hours. In my case it was within about 5 minutes of 10 hours.

Calibration

Ok, come morning it was time to calibrate. I was low this morning, which is extremely rare for me, but I know why. I have recently been able to increase my walking, and did 5 miles yesterday which drove my glucose down all day.

So, I took a glucose tab, and not long afterword, did the calibration, knowing full well I did not have a stable glucose as you are supposed to have when you calibrate. I wanted to really test the system.

The system started working a few minutes after I did the calibration. I was getting readings 58 points higher that my glucose meter said. I ate, the navigator gradually went up, as expected. Rock stable curve on the graph, no false readings, just not calibrated right yet.

2 hrs later was time for the second calibration. I did this, the system "noticed" it was way off, corrected the readings over a period of 5 - 10 minutes. It gave a reading of 102. My one touch meter used on my arm said 96. It also told me I would have to calibrate again in two hours, which is exactly the way things should be done, IMO. The documentation says you may be asked to calibrate again, in this situation it should.
Once I do this, the next one will be tomorrow morning (24 hrs) and then again on day 3 in the morning.

The sensors expire in November.

My Impressions

At this point I am extremely impressed with how it works.

The belt clip holds the receiver snugly. It does not swivel.
The neoprene cover (skin ?) is really nice, I expect that is what I will be using at all times.

BTW, the calibration at 2 hrs showed 3 pts difference between freestyle finger test and onetouch arm test (I was very stable).
Redoing the second calibration 2 hrs later, Navigator said 108, fingerstick freestyle said 98.
2 minutes later, my Navigator says 98 (it adjusted itself)

Accuracy

I did 15 comparison tests, against my onetouch ultra 2, alternate site testing on my arm.

Equal values reported 3
Difference of 2 points or less 4
Difference of 3 to 5 points 4
Difference of 6 to 10 points 2
Difference of 10 to 13 points 2

Further observations

The Navigator seems to lag a bit further behind than my alternate site testing on my arm, which itself has a lag compared to finger testing. This is somewhat offset by the ability of the system to predict when you will go low, up to a half hour ahead of time. The difference between arm testing and the navigator (on my arm) has not exceeded 13 points, so far, and the lower the rate of change, the closer the navigator is to matching my arm testing.

Data Communications

The receiver both sends and receives in bluetooth. The software for data management on your computer is awaiting FDA approval, they could not submit it until the Navigator was approved.

A note about connectivity between the transmitter and receiver. The specifications say it should work when the transmitter and receiver are up to 10 feet apart. I am happy to report I am finding it works further away than that. I think the actual Bluetooth specification itself calls for 30 feet. I have not measured this, and it would depend on the environment you are in anyway. I will say that in my experience, if the receiver is in the same room I am in, it has worked without fail.

Screen View-ability

In good lighting, the screen is fine indoors. No artificial lighting, daytime, indoors, it could stand to be a bit brighter, but is fine with backlighting turned on. Outdoors - absolutely great in bright sunlight, with or without sunglasses (that is unusual for displays).

Update:

This morning when I came in from my 5 mile walk, I removed my t-shirt, and the sensor and transmitter came right off my arm. I guess I will need to use the overbandage, or some tape. This is the second 5 mile walk I have been on, the first time there was not a problem.

I spoke with the very helpful people at Abbott, they are sending a replacement sensor. I would guess it is hard finding a happy medium between adhesive that sticks well enough, and adhesive that hurts when you remove it.

I have had a number of chats with the experts at Abbott, they are really good. There are tricks to doing things, like getting the transmitter to release from it's mount. It is not yet routine, but getting there.

I also spoke with someone in their data management department. The navigator will work with co-pilot, when that gets approval.

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Observations after 18 days of use:

The 10 hours time before you can calibrate after inserting a new sensor, seems to be on a timer. 2 hours later when you calibrate again, the reading is compared with your continuous reading, and if it is too far off, or if your reading is unstable (going either up or down), you will get a message that you will need to calibrate again in 2 hours, and that sets a 2 hour timer. This repeats until a successful calibration is made. While this can be inconvenient at times, it seems to be the cornerstone of the high accuracy that is achieved.

Most people will want to avoid starting a new sensor in the middle of the afternoon, because the calibration would need to be done in the middle of the night.

The graphs you get are very useful for seeing patterns. You can also look at readings at 10, 60, or 120 minute intervals. The 10 minute interval works well when accessing how your control was last night, for instance.

Observations after a month of use:

I have not had one false alarm, nor has the navigator failed to signal an alarm when it should.

-Lloyd