I’m a relatively new user to this forum but have been reading the posts for some time now. I’ve been a pump user for more years than I can remember and jumped on the CGMS wagon when it first came out as a separate Guardian system.
Let me first discuss the Minimed Paradigm CGMS system a bit. When news first hit that Minimed had released a CGMS system in limited markets, I just simply had to jump on it for my own peace of mind. I live in the northeast and flew down to Houston to purchase (out of pocket) the Guardian system, which, at the time, was separated from the Minimed pump.
To be rather blunt, the Minimed CGMS hasn’t changed much since back then. The technology is essentially the same and the sensors (oh, the sensors) are just as troublesome. This post is not meant to look at every single component nor is it meant to be an instruction manual, so I will skip the small details.
The Minimed sensors contain a very long and thick needle (I cannot stress this enough). I am a rather athletic male and have very little fat anywhere on my body. The sensors are inserted through an insertion device, which, quite literally, springs the aforementioned long and thick needle right into your stomach. With my physique, the majority of insertions resulted in extreme pain and quite severe site bleeding (my pants sometimes got blood stains from the dripping blood). I also quickly found that when there was excessive site bleeding, the sensors were worthless - they would not get a good signal. This was especially disheartening, not only for the physical pain, but the pain this process was on my wallet. My insurance considered CGMS systems experimental and did not cover the cost, with each sensor resulting in a $35 out of pocket expense.
Assuming a successful sensor insertion, I waited out the calibration period and entered my BG reading. In a nutshell, I have had an awful experience with the Minimed CGMS’ ability to accurately display BG readings. It was a false sense of security knowing that I had a CGMS sensor on me but which did not reflect accurate results. For example, it would not be uncommon to be in the 200+ range, bolus, approach hypoglycemia about an hour later (~90-100) and have the CGMS still reflect the 200+ range. Worse yet, the results gained some accuracy around the third day of use, which is also the sensor’s expiration date (72 hours). Often times, the sensor would not have a good signal or would lose it after a day or two of use. This resulted in false low alarms, with the CGMS system advising me that I was low when I was perhaps 50+ units higher.
The nice feature about the Minimed CGMS system is that it is housed within the Paradigm pump and does not require carrying two separate devices. However, this feature was not strong enough to hold me as a customer once I found the FreeStyle Navigator.
I ordered the FreeStyle Navigator through one of the authorized resellers. The ordering process was long and drawn out because of the multiple hoops that the patient is required to jump through. My reseller, in particular, was horrible (and still is). After hours of phone conversations and numerous medical documents, my order went through and my insurance billed. I received the device and opted not to partake in the formal training given my long history with the systems and my technical knowledge.
Setup was a breeze. After configuring the device with the necessary options, I took out one of the sensors. The sensor and its support bracket are attached to the insertion device. To insert, you simply peel off the tape backing, apply it to the designated area, and press a button. I simply cannot compare the insertion discomfort between the FreeStyle Navigator and the Minimed CGMS system because, quite simply, the FreeStyle Navigator does not have any discomfort! Most times I barely feel anything, other times it may feel like the prick of a lancet device. I have not ever had any pain or site bleeding.
The calibration period with the FreeStyle Navigator is quite longer (10 hours), but the sensor itself lasts longer (5 days). Once calibrated, however, I was absolutely amazed as to how accurate the device is. I am not getting into the technical specifications between the two devices (ie. the data refresh rate, frequency of calibration, etc.), but in all of these categories the FreeStyle Navigator wins hands down. The pattern trends are accurate and the displayed BG level is usually no more than 10-15 points off from a fingerstick reading (sometimes it’s as close as 3-5 points off!). I have had a few times when the device was not properly calibrated and the readings were consistently approximately 30 points higher than my fingerstick, but this was quickly solved by manually requesting a BG calibration. The sensor really does last the full 5 days and the results are just as accurate on day 5 as they are on day 1.
Now the bad. I had a few sensors that didn’t work due to errors, but a brief call to technical support resulted in a new sensor being shipped to me within 2 days. The sensor’s adhesive is not as strong as I’d like and, even worse, leaves my skin extremely irritated. By day 2 or 3, my skin is itching, red, and bumpy. I recently started to use a prep pad which creates a thin film layer over the skin. This greatly reduces the irritation but it does not completely solve the problem. The FreeStyle Navigator designers can really improve on this area. Also, the Navigator requires an additional, albeit small, device to carry around. This will be solved with the future integration between the FreeStyle Navigator and the Omnipod.
In summary, below is a list of pros and cons of each system:
Pros: Pump integration; small transmitter
Cons: Highly inaccurate results; extremely painful insertion; 3 day sensor life; 5 minute data refresh rate
Pros: Highly accurate results; painless insertion; 1 minute data refresh; 5 day sensor life
Cons: No pump integration; larger transmitter; extreme skin irritation
Having said all of this, I am EXTREMELY happy with my selection of the FreeStyle Navigator. It has really given me piece of mind and valuable information which I use to manage treatment. My only regret is not having found the Navigator sooner!
If you have any questions about either system, please post a reply or PM me and I will get back to you with an answer!