The Dexcom SEVEN continuous glucose monitor has been approved for 7 days of use. I usually get 10 to 11 days of use by restarting the sensor after 7 days have elapsed. Your results may vary, so make sure this works for you before relying on it.
Based on the abstract from the Diabetes Care website, it appears that the results on the 10th day are still fairly accurate. Notice how the difference goes down slightly on the 7th day, showing that the Dexcom is more accurate after it's been in place for a few days.
The median absolute relative difference for CGM versus YSI was 12.6, 11.3, and 14.5% on days 2, 7, and 10, respectively (P = 0.63). CGM performed better on day 10 when compared with self-monitoring of blood glucose as compared with YSI.
I expect to see more papers like this before Dexcom applies to the FDA for 10-day use of the sensors. The good news is that this ultimately means less sensors changes will be needed. It also probably means that Dexcom will raises the price of the sensors.
I do hope that before Dexcom takes this move they improve the adhesion of the sensors. Mine usually look like they're falling off by day 9 and they rarely last beyond day 11 because they peel off.
Have you been able to get sensors to stay in place for longer? What tricks have you used to make this work?
My shoulder has been killing me for the last few days. So far stretching exercises haven't helped all that much.
No problem you say, take a pain killer. That would work except...I'm allergic to everything except acetaminophen. And that causes my Dexcom readings to go haywire.
Within 20 minutes of a dose of acetaminophen (generic form of Tylenol), the Dexcom receiver reports super high readings. Quickly up to 400 and then into HIGH. That continues for about 6 hours in my case. And there's a long list of drugs that contain acetaminophen.
This is because acetaminophen changes the reaction that is used by the sensor to measure glucose values in interstitial fluid.
So I take my tablets and put the receiver far away from me for 6 hours or so.
How can I tell when it's safe to use it again? I carry it around for a few minutes and see if it's still reporting off the wall values. If so, I put it away again.
It's frustrating. If I keep it with me for the duration the high values throw off the statistics reported in the Dexcom software.
I've asked them to change the software so I can mark a set of readings as invalid. I think this is a relatively small software change. That way I can continue to use the receiver and my statistics won't be affected by 6+ hours of values over 400 mg/dL.
If you're having the same problem, do please call Dexcom customer support at 1-877-Dexcom4 (1-877-339-2664) and let them know. Maybe we can influence them to make this fix.
Note: I currently own shares in Dexcom, I work not to let this influence what I say about the company or its products.
I picked up the mail today and opened a letter from my wonderful endo (Dr. Elizabeth Spatola of St. Joseph's in Nashua NH).
Inside it was the latest A1C test and (....drumroll....) my A1c is 6.6%
For me this is the lowest value I've ever had, and I'm more thankful than I can say.
In 2009, I'd like to keep my A1C at around 6.6% for the year. I'm grateful that I can use technology (insulin pump, Dexcom CGM) and rely on many people at TuDiabetes and the entire Diabetes OC (online community) for support and advice. Without all my friends in the d-blogosphere, I think living with diabetes would be a lot harder.
In 2009 may your blood sugars be steady and your diabetes frustrations be few.
For all of us I hope to see some exciting diabetes research development in the next 12 months.
I was at a pumpers support group meeting last month. We listened to a presentation on continuous glucose monitoring from a Dexcom representative, and I was surprised to see she had a pink Dexcom receiver.
It turned out she had a skin for the Dexcom receiver. Apparently Dexcom made a small number of these in pink and blue. I managed to get a blue one from here, and started using it immediately.
I like that it protects the receiver from a certain amount of wear and tear. It does not make it waterproof.
Amalas's comment about the thickness made me measure the skin. It's 1/8" (0.32 cm) thick and weighs about 1/2oz (16 grams). The receiver already weighs 84 grams, so the skin adds almost 20% to the receiver weight.
Dexcom does not sell these at present. But I think they're a great idea (anything is better than black). Why don't device makers realize that we all like to personalize gadgets? Just look at what's available for cell phones or iPods. Heck you can even get laptop skins.
Why not contact your local Dexcom rep (ask your endo's office for a phone number) and tell them you'd like one of these? Who knows, maybe you'll get it in time for Christmas.
And while you're at it, tell them you'd like to see more of these. Personally, I'd pay $10 to make the ginormous receiver look a little better.
(Oh and I'm still waiting on a much smaller receiver.)
Dexcom has mentioned this possible market in presentations over the last year, so this was an expected market development for them.
Edwards Lifesciences will pay an upfront fee of $13 million and follow up with further payments for product development based on meeting regulatory milestones.
Dexcom's CEO has talked about a standalone Intensive Care Unit monitor in the past for in hospital use. But they also realize that the ICU is a crowded spaces and integrating the Dexcom system into existing equipment is important for product acceptance.
In intensive care, stress and other conditions means that patients' blood sugar control is often bad, even when they don't have diabetes. Tight glucose control leads to a faster recovery and better wound healing., leading to reduced costs and improved outcomes for patients. Currently about 25% of ICUs will try to do this using 12-24 fingersticks per 24 hours which costs a lot and keeps ICU staff busy. Using a CGM with programmable alarms leaves them with more time to care for patients.
In this agreement Edwards is responsible for sales and marketing. Given they already have a sales staff focused on the ICU market, this would be much more effective than growing an appropriate in-house staff at Dexcom. In return, Dexcom will receive a royalty of up to 7%.
For those of us, like myself, with Dexcom shares this might ultimately boost the share price which has been down substantially for some time now.
The New England Journal of Medicine has just published a paper on a JDRF-funded study showing how continuous glucose monitors impacted blood glucose control.
The study proved that CGM's resulted in better blood sugar control for people over 25. Hopefully this paper will be useful in supporting insurance claims for coverage of CGM devices. Maybe you'd like to send a copy(PDF) to your insurance company when you make a claim for CGM coverage.
I'm excited that this independent study of a relatively large number of people showed such good results. A few more like this, and it will be hard for companies to argue that CGM's are experimental devices. Dexcom summarized the paper like this:
Highlights of the study results include: -- Patients 25 years of age or older who used CGM showed significant improvement in glucose control as measured by HbA1c. -- Most importantly, this improvement in control was observed without an increase in hypoglycemia (low blood sugar), which is a common concern in intensively managed patients trying to achieve improved glucose control. -- In all ages, patients who used CGM at least six days a week had substantially improved HbA1c levels.
In addition to successfully meeting statistical significance for the primary endpoint of absolute A1c reduction, the adult cohort in the study – patients 25 to 72 years old – also successfully met all secondary endpoints with statistical significance (including A1c of less than 7.0 percent, A1c of less than 7.0 percent with no severe hypoglycemia, greater than 10.0 percent relative reduction in A1c and greater than 0.5 percent absolute reduction in A1c).
Younger patient populations did not see a statistically significant reduction in A1c. However, patients in those study arms used the Personal CGM device less often than prescribed (50 percent of the time or less). All patients, regardless of their age, experienced A1c reductions when they used the device at least six days a week. The most compliant study arm – adults 25 to 72 years old – used the device more than 85 percent of the time and subsequently saw the greatest improvement in A1c. These findings expand upon the results of previous studies – like the Star 1 Study – demonstrating that more consistent use of Personal CGM results in more significant reductions in A1c.
As I prepare for my fund-raising triathlon, I've been doing a lot of swimming. One problem that I had to solve was how to swim and monitor my blood sugar at the same time.
My Dexcom receiver has to be within 5 feet of the sensor/transmitter. That doesn't work when I'm swimming 1/4 or 1/2 mile distances. While the sensor/transmitter is waterproof, the receiver isn't.
I read somewhere about Aquapac and it's line of waterproof cases, so I measured my Dexcom receiver and ordered their mini class case.
When it arrived it certainly looked big enough for the Dexcom receiver. But when I tried to put the Dexcom into the case, the face would bind to the plastic. So I took a small index card, folded it, and slipped it into the case first. Then I could easily get the Dexcom receiver in place. I use the index card again when I want to get the receiver back out.
When I'm swimming, I use the cord that comes with the Aquapac. I can swim with the cord around my neck, and provided I keep it on the same side as the sensor, I get great readings during the swim. I can also see the values while I'm in the water.
For my triathlon, I leave it in the case until the end. That way I don't have to worry about damaging the receiver due to sweat or rain. I've used this case on three long swims (> 15 minutes in the water) and it's worked perfectly.
At the end of April I posted about the Dexcom Open Choice model. I was fortunate to get a loaner model for a short while. Since then I've been waiting impatiently to get the software update.
Dexcom had been offering a new system for an upgrade price. But I really didn't want to spend even more money on my third system upgrade in 15 months. Yes each of these have introduced useful new features, but knowing that they were going to allow you to upgrade for free made me want to wait. Apparently the delay was in getting FDA approval to allow this type of home update for an existing device.
Last week Dexcom contacted me and asked me to try out their software update process. They sent me two CDs with a new system manual and a new version of their DM system software. The upgrade also came with several pieces of paper including an important letter from Dexcom marketing with several steps that you need to complete before starting. I cover those below.
In a nutshell, the software update works well. I am now the owner of a Dexcom Open Choice model and I've switched to the WaveSense Keynote meter full-time. Goodnight OneTouch and the terrible cable (meant to sound like Goodnight Moon). From start to finish the whole process took about 15 minutes, including the download of about 3 weeks of reading from my receiver.
Dexcom marketing has told me that they're going to send upgrade kits to Dexcom Seven customers in order of purchase. Those of you who first bought the Seven will get these first, and folks who bought in February will get them last. They're going to send a letter out next week explaining the process.
There are a few gotchas to this update and I'll explain these as I show you some of the upgrade screens below. I'd recommend reading to the end of this post before starting.
You should:
Download all the readings from your receiver (it'll save time later).
Get the transmitter serial number from the receiver screen that's used to change it. It will be something like JTJLR, and you can see it without changing it. During the software upgrade process your receiver is completely reset. So you'll have to re-enter this number. You'll also have to restart your sensor, or change to a new one.
Make sure your receiver is fully charged. There are dire warnings about disconnecting during the upgrade and the process does drain the batteries some. If your receiver battery went dead in the middle of the update I think this would be a bad thing.
You'll have to connect to the internet to do the update. As part of the upgrade Dexcom gives you a keycode that you'll enter to get the new software. The value is similar to 2ABD-E512-3210 (this is not valid).
When you install the new version of the DM software and run it, there's now a new option under Tools menu in the upper right.
After you connect your receiver the update process starts and you'll see a screen with six steps on it, you cannot disconnect your receiver until all steps are completed.
At step 3 you're prompted to enter the code and the new receiver software is brought to your PC.
You can then download all your data readings from the receiver or just skip this step if you're downloaded beforehand
The receiver update then starts.
Several minutes later the update is done and you now have an Open Choice Dexcom model.
You'll need to re-enter the transmitter serial number and insert a new sensor (Dexcom's advice) or just restart the one you're using (my advice). After the usual 2-hour startup period you can now calibrate using whatever meter you wish. My YouTube video shows how this is done (skip forward to about 3:10).
I did this update five days ago and I've been using my restarted sensor since then. Being able to calibrate with the meter of my choice is a wonderful feature, but I've even more excited that Dexcom can now issue future software changes that we can make at home.
Note: I currently own shares in Dexcom. I try to make sure this ownership doesn't influence what I say about their products and technology.
My local Dexcom rep kindly arranged to give me a loaner of the new Dexcom Open Choice system. The main difference with this system is how it's calibrated - you can use any meter and enter the blood glucose values by hand.
I carried around both Dexcom receivers, the Dexcom 7 and the Dexcom Open Choice, for over a week. In this test I set them both to read from the same transmitter, so I could directly compare the results. Here's a short video that shows how to calibrate with the new system.
Below I've also got some details comments on the pros and cons of the changes.
I think this small change is a major improvement to the Dexcom system. It gives you the freedom to use your favorite blood glucose meter, so you don't have to worry about getting insurance coverage for two sets of test strips. The WaveSense Keynote meter that I used is extremely accurate, so I hope to benefit with better control and tighter A1Cs.
Dexcom updated their software so that the modal view is available once again. You can now see the reading graphs for up to nine days of readings. I've used this to see problems that happen at specific times each day. It was the only thing I missed from the first version of the Dexcom software.
I have two minor issues with the new features.
First when inputting the glucose value you use the up/down arrows to change the existing value shown by the Dexcom. The scroll speed for those arrows is much too fast. Most of the time the current value is going to be close to the reading from your meter. So you need to change the value only a little. The scrolling is so fast that it's only useful if the difference is over 100 mg/dL. Dexcom please reduce the speed here.
The other issue is even less important, it's to do with the location of the calibration screen. After you've removed and replaced a sensor the first thing you need to do is tell the receiver. You use the sensor insert screen that only appears when the receiver isn't already connected to a transmitter. Dexcom placed this screen after the calibration screen. It should be placed before the calibration screen. Most users will not be calibrating without a sensor in place.
The Dexcom Open Choice is being shipped to all new customers. Existing customers can pay an upgrade (about $200 currently). Dexcom is waiting for FDA approval to provide a download capability for software upgrades. The hope to get this approval by July and will then provide the upgrade for free to existing customers.
Update: I received the software upgrade from Dexcom so I could give them feedback on how it worked. Read more on my post about the Dexcom Open Choice upgrade. They will start shipping the upgrade to all Dexcom Seven users soon.
Note: I currently own shares in Dexcom, I try not to let this ownership influence what I say about the company or its products.
I use this term for a product that you may already like that then surprises you with a feature that you didn't even know existed. Like a car that turns off the interior lights before the battery runs dead, even if you'd left them on by accident.
I had one of those experiences today with my Cozmo. Yesterday my pump had started to complain that the battery was almost empty. And today I was running on voltage fumes.
I knew that I had to replace it, but I kept forgetting to. That is, until I was putting in a combination lunch and correction bolus. While the pump was delivering the bolus I decided to test what would happen if I removed the battery, essentially mimicking loss of power.
After replacing the battery I was pleasantly surprised to see a Bolus Interrupted message on my Cozmo. This is the kind of attention to detail that I've seen in other parts of the Cozmo pump. Those firmware engineers (the folks who write the code that runs the pump) really thought about this - good for you folks!
Dexcom delights
Another customer delight for me, this time from those great Dexcom folks. Today I got the new Dexcom CGM model to try out for a week or so (one sensor life). I'm going to replace my 16-day old sensor this evening and tomorrow I plan to try and use both receivers against the same sensor and see what happens. I'll use the OneTouch meter with the older receiver and my AgaMatrix WaveSense meter to calibrate the newer receiver.
What I'm hoping is that the newer receiver will show my readings to be higher that on the older receiver. If I'm right then it may prove my theory for my A1C being higher than expected.
The trial model also came with the slightly newer version of the Dexcom software. They've re-introduced the modal day view, which is very useful when you want to see recurring patterns in a number of days.
I'll blog about the new receiver and software after I've had a chance to play with it for a few days.
Update: I've posted a video on YouTube showing how to calibrate the Dexcom open choice. I still need to talk about the software.
Note: I currently own shares in Dexcom, I try not to let this ownership influence what I say about the company or its products.
Recently I put together a table for my endo. It showed how my blood glucose numbers had changed month to month since I started using the Dexcom. I was able to use the Dexcom software to get this information, based on its readings.
I wanted to show it here for a few reasons. (And apologies to anyone who is vision impaired. Blogger does a lousy job with tables, so I had to post a screen snapshot of this.) First of all, my average (Mean column) is improving most months.
My standard deviation (SD column) is also improving. Here standard deviation indicates how tight my control is. It is now more accepted that tight control may mean less complications. If I can keep my standard deviation to about one-third of my average value, then my control is tight. And I'm nearly there.
In the last column I've shown my A1C values. Again there's improvement there, but not as much as the averages would predict. A blood glucose value of 135 mg/dL should give me an A1C of about 6.0%.
This is why I believe the Dexcom readings are lower than my true blood glucose values. And I blame that on the meter it's being calibrated against. Hence my impatience for the new Dexcom model.
It still amazes me how much those of us with diabetes focus on numbers. It's not like we have a choice. We test several times a day and then do some calculation with the numbers to decide how to correct (carbs or insulin). We try to guesstimate the amount of carbs in the food we're eating and how much insulin we need to cover this. We're constantly calculating to try and be substitute pancreases.
I look forward to the day when we're no longer forced to be math geniuses.
Some time ago I mentioned the upcoming release new version of the Dexcom. It will let you calibrate the system without needing that darn cable. You can also use any blood glucose meter. Dexcom calls this 'open coding' and it is meant to be available around March 2008.
There two big advantages to this small change:
You don't need to carry the darn cable anymore
You can calibrate the Dexcom using any blood glucose meter
So why do I think this is such a big deal? Bear with me while I give a long explanation.
Last year I saw my A1C levels improve from April (just after I'd started the Dexcom) to July. But in October my A1C was back over 8.0%. That means my average blood sugar was around 200 mg/dL. However the Dexcom software said my average blood glucose was around 152 mg/dL, equivalent to an A1C of about 6.5%. That's a huge difference. One of the numbers must be wrong...or could they both be right?
Here's how I think the problem arises.
I calibrate my Dexcom with a OneTouch Ultra blood glucose meter. Like most meters, it's accuracy is about plus or minus 20%. (This is what is 'acceptable' according to standards for blood glucose meters.) So if it reports my blood glucose(BG) was 150, it's actually somewhere in the range of 120 to 180 mg/dL.
When I calibrate the Dexcom with it, the Dexcom uses that information when it calculates as my BG values. From experience I know that the Dexcom has a tendency to slightly low ball the numbers. So when it reports my BG at 80 mg/dL, my meter is likely to say it's around 95 (effective range 76 to 114). Result - I'm using a meter with a lowish accuracy to calibrate a continuous glucose monitor that's also got a lowish accuracy.
Perhaps my A1C is high, because I'm carefully using inaccurate systems to keep it within a tight range. It's just the wrong range!
I was given a WaveSense meter last year to review. I liked it a lot, it has a really good design and is easy to use. I even put a YouTube video up that showed the WaveSense in action. The folks had clearly put a lot of thought into the meter. The big thing about WaveSense meters is their accuracy. They certainly conform to ISO standards, all readings are within 20% of the true value. But with these meters, most readings are also within 10% of the real number. So if it reports my BG level as 150, then it's almost definitely between the range 135 to 165 mg/dL. That's way better, to my mind, than the 120 to 180 range for other meters
One thing I noticed whenever I used the WaveSense is that it would frequently give me a higher reading than the other meter I was using at the time. At the time I thought this was strange. Now looking back on it I realize that this is probably because of the WaveSense's better accuracy. The other meter was giving me a slightly lower, but less accurate, reading. Which made me correct with less insulin because I thought my BG was closer to the target that it really was.
When Dexcom allows me to use any meter I want to, I'm not going hesitate. I'll switch right over to the WaveSense meter that I've been using as a backup ever since I got it. That'll give me a third advantage: better A1C results, I hope!
I can't wait.
Update: I got to try out the new Dexcom model for about a week and I've posted about the Dexcom Open Choice with a video and my thoughts on the changes. Good stuff Dexcom.
Note: I currently own shares in Dexcom, I try not to let this ownership influence what I say about the company or its products.
Today the two companies announced that they will work together to integrate Dexcom continuous glucose monitoring into Animas insulin pumps.
"The new technology will enable the Animas® pump to receive glucose readings and display this information on the pump’s color screen. Users will have access to real-time glucose readings and trending in addition to receiving alerts for low and high glucose readings. Having real-time readings displayed on the pump screen will not only allow users to make more timely adjustments to their insulin delivery – it will eliminate a separate receiver, reducing the amount of equipment required to use CGM and the pump system."
According to the news report this should be available in 2009 or early 2010. And again it's a non-exclusive agreement, leaving Dexcom free to work with other pump makers.
Today Dexcom, who make a continuous glucose monitoring system, and Insulet, who make the OmniPod insulin pump, announced that they will work together to integrate Dexcom's CGM capability into the OmniPod's handheld system controller, the Personal Diabetes Manager. This will take time. According to the press release "Development, clinical and regulatory efforts are expected to continue throughout 2008, with an anticipated product launch in mid-2009."
The agreement is not exclusive, so Dexcom may also work with other insulin delivery device makers to combine with their technology.
I know that I've been very quite on the blogosphere for the last several weeks. I appreciate more than I can express all the comments and e-mails asking me how I'm doing and wishing me the best.
I won't bore you with the details here except to say that I'm in the middle of some type of depression. It's not earth-shattering and for those of you who have diabetes, it's probably not entirely unexpected. Taking care of a chronic disease is a big burden and it takes its toll. The good news is that I'm working pro actively to get this under control and get through it. And in the meantime I'm focusing on essential activities because I've not got a whole lot of energy for other things.
It's been a busy year on the blogosphere and busy one for me. I've been blessed with a lot of accomplishments over the last year, in no particular order:
I met Allison and Mel in Boston. It's always fun to get together with fellow diabetics! If you're going to be near Boston in 2008, please let me know.
I got to some meetings of the insulin pumpers group that meets in Woburn, MA each month. A fun, supportive and informative group. Every state should have a group like this.
I marked my 35th year with diabetes by raising over $11,500 for research in a diabetes bike ride. Hint: it's not too late to support this.
I received an award from Lilly and Joslin for 25 years with diabetes. Thanks Dr. Spatola for organizing this one.
I setup the diabetes search engine. It now indexes over 800 sites and I like to think that it's helpful for folks.
I joined the great TuDiabetes.com social networking site for diabetes. Big kudos to Manny for starting this.
I worked together with Beth to start the diabetes365 project (originally her idea). As of today there are about 1,750 photos that give some insight into what it's like to live with diabetes.
I almost completed NaBloPoMo for this year. I didn't post for every day of November. Next year will be better.
I started using the Dexcom STS continuous glucose monitoring system and moved to the Dexcom SEVEN system later in the year. Life with a CGM is a lot easier, though it still has its frustrations.
And of course I posted many blog entries. Along the way I hope that I informed some readers. I know that I learned a lot from your comments and I also managed to get lots of practice with my writing skills.
So what's in the cards for 2008?
I'm getting some blood drawn in January as part of the research for Dr. Faustman's work on a possible cure for Type 1 diabetes. No, I'm not getting an early version of the cure, I'm just donating blood samples for the work. I hope to meet her and ask a few questions, I'll let you all know what I learn.
I'll keep blogging, though maybe a little less.
I hope to get involved in another fund-raising bike ride in September.
I'm guilty. Even though I'm in NaBloPoMo, I didn't get a chance to post yesterday.
Like most of you, I was travelling late on Wednesday. And I was changing time zones. As I got on my plane, I had to chance the time settings on my insulin pump, my Dexcom and my blood glucose meter. One of the many joys of a diabetes geek. And when I'm travelling home on Sunday, I'll be setting them all back.
So besides the toll on my body, I guess my insulin devices will be out of sorts for a while. It could be a lot worse.
As I'm on the road, I have to keep my posts on the short side. But I'm taking a few different pictures for diabetes365 and I'll post these with a longer update early next week.
One note for Dexcom users. The new Dexcom sensor sets off the security wand at the airport if they decide to wand you. I don't know whether it also sets off the security scan as I had several things that might be the culprit there.
I'm still recovering from lost sleep due to the World Series. Remember I come from Ireland originally, so I'm still really learning about baseball. But having the Sox win in 2004 really got me interested.
And then there was the final game on Sunday. It's 11:30 at night and we're heading towards the end of the game.
Thanks to my Dexcom CGM, I'd watched my blood sugar heading lower. But I didn't want to miss the game to correct it. Finally I tested with my OneTouch, and it pretty much agreed with the Dexcom.
So I had to run downstairs to get some quick-acting carbohydrates to bring my blood sugar up to a normal range.
About 30 minutes later my blood sugar was closer to 100 mg/dL and the game was over. Victory for the Red Sox and a safe enough blood glucose reading that I could go to sleep.
There's no cure for diabetes. Yet.
If you've got diabetes and would like to show others what it's like to live with it, please join the diabetes365 photo project.
Diabetes365 day 10 Wednesday, October 17, 2007 - Test before driving
Most days of the week I get into a car to drive at least twice. And before I drive I need to check my blood sugar and make sure it's both stable and at a value that's safe for driving.
This is one of many things that I do slightly differently because of my diabetes.
I have hypoglycemic unawareness so I can't tell when my blood sugar is low. Driving without testing might mean that I'd be driving while not fully in control of the car. My reaction speed would be lower as would my ability to safely judge situations.
Because of my Dexcom continuous glucose monitor testing only requires a button press. This is a lot easier than having to use a blood glucose monitor yet again during the day! And is one reason why I like that device so much.
There is no cure for diabetes. And most insurance companies don't count test strips before driving in their calculations of the number of strips you need a day.
Do you have diabetes and can you take photos? Maybe you'd like to take part in the diabetes365 photo project.
I just read on the Yahoo! diabetescgms group that Dexcom has a special price on their system through September 28th. Instead of $800 for the system, the price until September 28th (tomorrow) is $350. Update is that it's $450. Remember this cost does not include any sensors. A four pack of sensors will cost you an additional $240.
This seems like a great deal for a system that works well for the most part. But before purchasing it, I'd suggest asking if there is any guarantee that allows you to return it within a certain time if it doesn't work for you. CGM systems are not for everyone. And the only way you can figure this out is by trying one.
Apparently the deal is being kept quiet. Contact Dexcom at 1-877-DEXCOM4 (1-877-339-2664) for details. And let me know if this rumor is not true.
Note: I still own shares in Dexcom. I try not to let this influence what I say about about the company or its products.
Today I'm at home in bed. I've already slept for most of the morning.
Cold? Flu? Stomach bug? Nope, this time (for a change) it's really due to diabetes.
I ate a relatively carb free meal last night. When I woke up at 1 AM with my mouth like sawdust thinks immediately didn't feel right. My blood glucose was 301 mg/dL. So I dutifully bolused, adding an extra 15% to the dose because correcting those super highs definitely takes more insulin. I even used a Super Bolus to move some of my basal delivery forward. Drank about 20 ounces of water and went back to sleep.
Woke up again around 4 AM. Mouth still sandy. Blood glucose had dropped to 258. Clearly all was not right with my insulin delivery. So I took a correction shot using an insulin, ripped out my infusion set and replaced it. And added some additional units of insulin. Having my Dexcom gives me more freedom to slightly overdose because it will wake me (or my wife) if I go too low. And downed another 16 ounces or so of water.
Woke to the alarm at 6:15. Tested and it was...246. What's going on?? At this stage I'd taken almost half my normal daily dose between the hours of 1 AM and 4:15 AM. Looked at my new infusion set and it had blood in it. So ripped that one out and replaced it. And drank more water.
Note: Drinking a lot of water when my blood sugar is high is something I learned many years ago. It helps your body reduce the sugar concentration in your bloodstream and it eases the strain on your kidneys of taking the sugar out of your system. Plus high blood sugars give you cotton/sawdust/sandy mouth and you just need water. But don't stop at just one glass.
Looking at my Dexcom, my blood sugar had been above 240 since before midnight (sometimes a lot above). I felt lousy. So replaced my infusion set again and overdosed slightly again and went back to bed.
No breakfast, high blood sugars and feeling exhausted definitely put me on the candidate list for a sick day. I managed to sleep from 9:30 till noon and feel a lot better. Having blood sugars under 150 is priceless.
Moral of the story. Sometimes diabetes just wears you down. Now if I hadn't been using an insulin pump I might have been better off in this case. But this kind of stuff only happens may once every two years or so. So I'll take it over constant shots.
I know where the week went. After a lovely Labor Day, I've been taking the children to school. Which means I've been adjusting my sleep schedule. And that's just...tiring.
Anyway, here are some random things.
Terry Keelan has a poll on TuDiabetes asking how people tape up their Dexcom sensors. For those not in the know, the Dexcom 7 continuous glucose monitor has sensors that can be used for more than seven days. I previously blogged about how to reset the receiver to do this.
But one of the problems is that about day 7 the adhesive on the sensor starts to fade. So how do you tape it up to keep it on. Inquiring minds would like to know. Have a look at the picture Terry provided
Then go to TuDiabetes and let him know your technique for keeping Dexcom sensors in place.
Some time ago I created the Diabetes Search Engine using Google's Custom Search Engine facilities. I think the DSE provides very useful results when you want to search about anything related to diabetes. Building the engine was a little tricky, so I wrote an article about the process. The article was published today on O'Reillys ONLamp.com web site. Warning, the contents are strictly for Geeks with Diabetes. You have been warned.
Finally, this weekend in Connecticut is the big ride. I've already raised over $10,000 to support the important research by Denise Faustman into a cure for Type 1 diabetes. But you might like to stop by and cheer the riders on. The race is in New Canaan and most riders will be coming back between noon and 12:30. Maybe I'll see you there. I'll be the 50-year old diabetic with the big grin on his face! And hey, it's not too late to support me.
I got two similar questions recently about the Dexcom 7 continuous glucose monitor (CGM) and I realized it's probably worth summarizing what I know about it for those who might be interested in using one. So here's a fairly long post with most of what I know about this interesting device. Note that the Dexcom 7 is officially approved for use in adults, but there are some folks on that list who are using it successfully with their children.
For the record. I start using the Dexcom 3 in March 2007, after a one week free trial. I switched to the Dexcom 7 on July 24th 2007 and have been using it ever since. After 35 days I'm on my 3rd 7-day sensor, so I'm getting an average of at least 12 days out of each one. Remember the sensors are approved for 7 days of use, but most people continue to use them after the seven days are up. I'll post in the future about how to do this, because it's not immediately obvious for everyone.
There are several bloggers who have posted a lot about their Dexcom experiences. You can find a list using the Diabetes Search Engine. Anthony has his Dexcom Seven blog, and Clemma has her Comrade Dex blog, both of which are very informative.
Trying out the Dexcom
You should not purchase a Dexcom without first trying it out. The cost of a Dexcom 7 system with four sensors is $640. And each box of four sensors is $240. And, no you cannot buy these individually.
I do not (yet) have insurance coverage for the Dexcom or the sensors. I'm hoping to start filing for this sometime during this week. From the Yahoo! diabetescgms group it sounds as if more companies are starting to cover the costs of this system. Unless you know that your insurer actually covers it, you need to consider the ongoing Dexcom sensor costs ($60 each for at least 7 days) before deciding to use one.
On the Yahoo! diabetescgms group, someone pointed out that CGMS users seem to be broken into 4 groups.
Those for whom the Minimed REAL time works well.
Those for whom the Dexcom 7 works well.
Those for whom either system works well, and
Those for whom neither works well.
Unless you try it out, you can't tell whether it will work for you. Contact your endo's office and see if they'll arrange a trial for you. You will need a prescription from your endo before you can get a trial. Originally I tried out the Dexcom 3 for a week, which allowed me to make a sensor change. I think this is crucial, so make sure you get to try out the Dexcom 7 for at least 9 days, ideally aim for 2 weeks. And make sure you get a copy of the software when you're doing the trial, the system is much better when you can actually use the (PC-only) software.
Sensor Insertion
Inserting a Dexcom sensor takes some work. With the Dexcom 7, the insertion is a lot less painful than with the Dexcom 3, but it's still tougher than for a pump. There's no spring-loaded inserter, you just have to jab it in. I continue to use it in my abdomen, but I know several people on the Yahoo! diabetescgms group have used arms and buttocks.
Once the sensor is inserted you connect the transmitter to the back of it. This combined unit is waterproof, and you can shower or swim with it and don't need to cover it in any way. The waterproofing is done by having the transmitter lock very firmly in place on the back of the sensor. You can only remove it using the plastic 'safety lock' that stops you from first accidentally inserting the sensor.
The Dexcom requires care and feeding. You need to calibrate it at least twice each day with a test taken using a OneTouch Ultra meter. Calibrating means you take a test with the OneTouch and then connect the OneTouch to the Dexcom via a supplied 5-foot cable, the synchronization takes about 10-15 seconds.
Alarming
You can change the alarm settings on the Dexcom with one setting for the low alarm (changeable in 10 mg/dL increments) and one for the high alarms (20 mg/dL increments). There's a hard-wired alarm that triggers at 55 mg/dL.
Except for the hard-wired one, the alarms only trigger each time the readings cross the boundary from normal to high or to low. So if your high alarm is set to 160 and the reading goes from 155 to 164, the alarm will trigger. If the Dexcom is reading 210 an hour later and the numbers never went below 160 you will not get another alarm. In the case of the hard-wired alarm, you'll get another one 15 minutes after the first.
The alarms can be loud. The first one is a loud buzz. If you miss it, or don't acknowledge it the next alarm is a loud buzz and noise. This happened to me yesterday and three co-workers in surrounding cubes wondered what it was and whether I was OK. So if you're easily embarrassed, watch out for this. In a recent webcast, the Dexcom CEO mentioned that the next generation Dexcom (no idea on dates) will have must more customizable alarms.
The Receiver
The receiver unit is fairly large, a little bigger than most of the insulin pumps available today. I usually carry it in my jeans pocket. It comes with a carrying case, but this is basically unusable. It sticks out very far from your belt and you can't connect the sync cable to it while it's in the case. And remember that it needs to be within 5 feet of the transmitter, so carrying it in a purse may not work.
The Dexcom receiver must be synchronized with a OneTouch Ultra meter at least twice a day. The recommendation is that you check your blood glucose using the meter before making decisions based on the Dexcom readings. In practice I probably test an average of 5 times a day, so don't expect a huge decrease in finger sticks because of the Dexcom. Note that Dexcom provided me with the OneTouch Ultra when I purchased my Dexcom 3 system, I assume they're still doing the same with the Dexcom 7. I also know that many insurance companies won't cover you for two makes of test strips. So if you're going to use the Dexcom, you're forced to switch from your current meter to the new one. The good news is that the Dexcom software will show you both the Dexcom system readings and the meter readings.
The picture below shows the 9-hour graph from the new and the old Dexcom receivers.
You need to charge the receiver about every 3 days, with the supplied charger. It's about the same size as my cellphone charger. I generally do this at night by plugging it in and then sleeping on top of the charging cable so the Dexcom can be beside me in bed. When sleeping I usually leave the Dexcom beside me because the receiver needs to be within 5 feet of the transmitter/sensor. And leaving it on my night stand means I may not hear it when it alarms.
With the Dexcom you'll get their new data management software. I complained loudly on this blog about the original DM software. The new version is much better with lots of useful and useablestatistics. You can also export the data as an XML file, or a comma-separated values (CSV) file which Excel can read.
What do I think about the Dexcom?
In April 2007, I described this as like having a superpower. And I still feel like this about it. My April A1C, just after starting the Dexcom, was 8.2% and my July A1C was 7.0%, a 15% reduction. I don't think I could have accomplished this without the Dexcom. It's also partially due to using Symlin more, and I really found the Dexcom invaluable to help me manage using Symlin.
For me, this has been a life-changing device. Diabetes management has become a lot easier all round. But there are also times when I want to throw it out the window. If I'm woken in the middle of the night (tonight) by a sensor alarm, it can be very annoying. If the usually smooth graph starts to have a lot of gaps in it for no reason that's also a pain.
But I'll stick with it, and I'm aiming for a further improvement in my A1C.
I hope this writeup helps you some in deciding about this device. Note: I still own shares in Dexcom. I try not to let that influence what I say in any of my posts.
When I got home last night a surprise was waiting for me. No, not the Harry Potter book -- that was earlier in the weekend.
A box from Dexcom was sitting on my porch, the new Dexcom 7 CGMS had arrived. The box contained an updated Receiver, a transmitter, and the new software box including download cable. I didn't get a new recharger, and unfortunately they didn't provide a shorter cable to connect the Dexcom 7 receiver with my OneTouch Ultra meter for synchronizing.
So I read the instruction manual while eating my dinner. Then I plugged the receiver in for a few hours to charge it up. I decided to insert the new sensor around bedtime. And wow that was a lot easier for me. That small change they've made in the sensor needle gauge made the insertion pain feel a lot less for me.
The Dexcom SEVEN transmitter design changed slightly. It now has two small extensions on the back to lock it into the sensor. This much be part of making the system waterproof. This did make it a lot harder to actually lock the transmitter into the sensor. The little piece of plastic left after sensor insertion really just didn't work.
Luckily I have such wonderful stomach muscles (hah!) that I was able to just push the transmitter into place. It was really tough! It'll be interesting to try and remove it in when the sensor is all used up.
I waited until this morning to tell the Dexcom 7 receiver about the new sensor. A lot of people have reported better results if you wait more than 2 hours after insertion of the sensor.
Dexcom has made several small changes to the screen between the Dexcom 3 and the Dexcom 7. All of these improve it greatly. They've replaced the time range on the Dexcom 3 (9:30 AM to 10:30 AM) with just the current time (10:30 AM) in a larger font and 1 Hr in an even larger font. Net result, it's much easier to figure out which screen you're looking at.
They've also changed the screens you use when telling the receiver that a new sensor is available. I think this will mean less confusion between the sensor insertion and sensor removal screens.
I've posted a short (and slightly fuzzy, sorry) video on YouTube that shows some of the differences between the screens. I'll try and most more about differences between the Dexcom 3 and the Dexcom SEVEN tomorrow.
Note: I currently own some shares in Dexcom, I work not to let this influence what I say about the company or its products.
According to the page the Dexcom SEVEN was approved on May 31st, and a pointer to the approval letter(PDF) is provided. So Dexcom really didn't delay at all before telling us about it.
It's interesting to see the history of the Dexcom filing with the FDA
Filed: June 9, 2006 Amended: July 11, August 4, November 21, November 24, and November 28, 2006, and February 9, April 20, and April 23, 2007
I don't think this amount of filing is unusual, but it gives some insight into the amount of work needed for FDA approval.
Two points in the background notice jump out for me. The first I already knew and the second is a little vague:
Use of acetaminophen-containing medication when the STS-7 sensor is inserted may affect the performance of the device.
The Dexcom STS-7 System must be removed prior to MRI
Does this mean that I need to remove the sensor and the transmitter before an MRI, or that I just need to remove the transmitter? I'll have to clarify that one with Dexcom. Update: I exchanged emails with Dexcom customer support. When having an MRI I need to remove the transmitter and sensor and leave the entire system in another room.
If the FDA only points out issues with acetaminophen, then it appears that use of other drugs doesn't cause issues. That's good, because I've already seen the impact of acetaminophen on the Dexcom STS that I'm wearing and it's not good.
I'm still waiting on my Dexcom SEVEN. I hope to see it in a week or so.
Note: I currently own some shares in Dexcom, I work not to let this ownership influence what I say about the company or its products.
I've spent a good deal of time over the last week on the phone with the local sales rep from Dexcom. I was trying to negotiate either a loan of the Dexcom SEVEN, or a deal where I could purchase it and return it if I wasn't satisfied with the new features promised.
I was disappointed before by a promise made by the previous Dexcom representative and I really didn't want this to happen again. But thanks to the great posts on the Dexcom SEVEN by Clemma, I'm now more confident that I'll really like the new features, and I can live without an improved display for now.
The big outstanding question is how long the new Dexcom SEVEN sensors will last for. I'm on day 11 of a current 3-day Dexcom sensor. So to get the equivalent performance from a 7-day sensor, I'd need to be able to wear it for about 25 days. I don't see this happening. So I'm going to work my insurance hard about reimbursement.
It looks like the new software is much better. The representative tells me that you can export the Dexcom data to an Excel spreadsheet - he'd better be right. The waterproofing will be nice and the reduced gauge needle.
What else should I tell you about? Oh yes, the upgrade price. Officially the entire new system (receiver, transmitter, cable, software, One Touch meter) is $800. They currently have a special upgrade offer for July. Over the last week, I got three versions of the upgrade price.
Last week Dexcom sales told me it was $350. Yesterday the Dexcom representative told me it was $450. But late yesterday when I called Dexcom sales to order the system, I was told the price was $150!! So that was what I paid. I also ordered 4 sensors at the special price of $175 (instead of $240). So for about $343 plus tax I'll get the new sensor, receiver, and software. I'll have to return the old ones.
Other minor piece of new is that they're all out of upgrade kits. So right now I need to wait for about 2 weeks to receive it. Once I do, I'll be sure to let you know what I think of it.
Note: I currently own some shares in Dexcom, I work not to let this ownership influence what I say about the company or its products.
I had my first meeting (by phone) with him last week. Today was a great day, and I think some of that was due to the suggestions that he made about changing some pump settings. Here's the proof, thanks to my Dexcom STS.
I'm hoping to get a few more days like this from here on out. I'll let you know how it goes.
During this week I've read more about the new Dexcom SEVEN continuous glucose monitor that was approved back in May.
I see some traffic on various mailing groups and I've spoken with Dexcom service/sales about the new device. So I now have a little additional information that I wanted to share (because there's so little out there in webland).
The new system appears to be available now. The person at Dexcom that I spoke with was ready to take my order on Friday.
The upgrade price for the system is $350. This includes new receiver, transmitter and software. You'll need to mail in the old transmitter and receiver. You'll receive a reconditioned receiver.
Warranty on the upgraded system is one year.
The price for a box (four) of new sensors is $175 when ordered with the upgrade. Future boxes are the full price. I think this is still $240 for a box of four.
The software is much improved. It can read data from the current Dexcom system as well as the Dexcom SEVEN. It includes statistics that can give you an hourly breakdown. I don't know whether it supports data export yet.
The receiver has not changed much. It still shows a graph of readings from 50 to 400 mg/dL. Major change is that it now shows you how long until the sensor expires.
I don't know how long the new sensors last beyond the official 7-day life span.
That's all the details that I have right now.
I hope to get the new system to try out for two weeks before purchasing. The software is the current Dexcom system was such a disappointment that I won't upgrade without trying the entire system out first (including software).
In the meantime, if you're already using the Dexcom SEVEN why not let us know what you think about it? Maybe you could post about it on the CGM Users group on TuDiabetes?
Dexcom has just announced that their current CEO, Andy Rasdal, is being replaced by Terrance H. Gregg formerly of Minimed and Medtronic.
I have to believe this is a good move for Dexcom, maybe it's part of the reason their shares have been up a lot in the last 2 days. Terrance will bring a lot of business expertise appropriate to that specific market to Dexcom.
And according to their recent webcast, Dexcom is set to publicly launch the Dexcom SEVEN on June 23rd. That seems to be when people will start to get hold of it.
These are exciting times for Dexcom. I just hope that the Dexcom SEVEN has enough improvements over the Dexcom STS to actually justify the hype.
Note: I currently own some shares in Dexcom, I work not to let this ownership influence what I say about the company or its products.
This Monday at 1:30 PM (PDT) Dexcom management will be having a conference call to discuss the approval and launch of the Dexcom SEVEN CGMS. Hopefully this will answer some of the questions raised during the earlier announcement about the FDA approval for this system.
The number and codes have changed for this call. The new numbers are given below.
The number for the call is (866) 290-0920 (US/Canada) or (913) 312-6670 (International). And the participant code is "7146581". You should dial in about 1:25 PM (PDT). This seems to be a listen-only line. Does anyone know what number to call so you can ask questions?
The conference call will also be webcast. You can find the link to the webcast on the Dexcom webcast page. You can go there today and pre-register for this call.
I'd like to know the answers to the following questions:
When will the Dexcom SEVEN system be available to consumers?
Will the new software be available on the same date? If not, when will the software ship?
What's the pricing for the system and sensors?
What's the upgrade pricing for the new system?
I hear the transmitter and sensors are waterproof. Is the receiver also waterproof?
I'd like more details about the software. Does it provide statistics, including the the average, and standard deviation for blood glucose values? Does is allow access to the data?
If this is such great news, how come the stock price is still depressed?
I'll be camping at the time. So I'll wait and listen to the archive later in the week.
The updated Dexcom press release doesn't give much more details than I reproduced here.
What questions would you ask Dexcom, if you could? Perhaps you'd like to e-mail them to Jessica Ching, Marketing VP for Dexcom. Her e-mail address is jching@dexcom.com.
Note: I currently own some shares in Dexcom, I work not to let this ownership influence what I say about the company or its products.
I know you're going to think that I've lost my mind. Because what I'm complaining about may not seem that important to you. But it is probably a lot more important than you think. So bear with me.
On Tuesday, I went for an eye doctor appointment to see what was going on with my right eye. I've had some blurriness in the central part of my vision for a while. So the doctor decided to take some pictures while injecting a fluorescent dye into me. That way if there are any issues, they'll show up clearly in the camera.
Now being a geek, I thought this was way cool. I asked the man doing the pictures whether I could get copies of them. I figured the kids would be interested in them, and I might post one to the Diabetes Made Visible photo group on Flickr.
Well he mentioned that I'd need to fill out some paperwork and then he could print me some copies. But I didn't want paper copies. I wanted the high resolution photos that I saw on the screen in front of me. So I said, "well I just want to take them home on a Flash drive". His immediate response is "no, you can't take the files".
Now it's not like I'm removing them. I only want a copy. When I pushed him on this, he said they're "scared what you might do with them". Now can you think of something terrible I might do? Print big posters and e-mail to folks causing heart failure? What's possible bad thing could I do with close up pictures of the back of my eyes?
So that's bad data day item #1. Oh, and by the way, there's no significant damage to my eye. So we're just going to keep watch on it (pun intended).
After I got home, I spent some time talking with someone in Dexcom. I'm trying to get one of the new Dexcom SEVEN systems with software, so I can review it.
The response is that right now they're trying to get training ready for the systems. So there are none available for review.
While I was talking with this woman, I asked why Dexcom is making it so hard for us to get to our data. Her response is that it's due to FDA restrictions.
This is bad data item #2.
I'm checking now to see if the FDA remark is actually true. I can't find anything in various advisory committee transcripts about this. I've fired off notes to some contacts within the FDA. I'll let you know what I find out.
Did you read my post about Google and health issues? Now how can we get access to our data if you have 'the' diabetes hospital (Joslin Clinic) saying "you can't have your files". And if the FDA or a device maker is saying "you can't have your data".
I'm just steamed about this!!
How can we improve things with a shrinking supply of endocrinologists, and without access to the facts we need to improve our control?
Grrr!!
Update: I currently use four pieces of diabetes-related software. All of them have the data locked down in some way.
Dexcom: Data encrypted or in binary form (unable to crack -- so far)
OneTouch: Data password protected (easy to crack)
MiniMed: Data password protected (easy to crack)
AgaMatrix: Data password protected (easy to crack)
So I think this is a widespread practice. But I can't figure out why.
Finally (because I've been waiting for it), Dexcom received FDA approval for both it's 7-Day continuous glucose monitoring system and it's next generation software to go with it. Though it will be a while longer before most of us see it.
The company press release doesn't provide much additional details besides the fact that the new sensors are approved for seven days of use.
But there's also a product announcement webcast from Las Vegas. It's over 39 minutes long, and does not come with any additional slides, though there were slides shown during the presentation.
In the remainder of this long blog post, I've summarized what I picked up from listening to the webcast.
Webcast Summary
In the webcast Andy Rasdal, CEO of Dexcom says that there were no conditions from the FDA on the approval. Dexcom plans to have a limited launch of the new product offerings (presumably both hardware and software) at the end of this quarter with a full launch in the 3rd quarter.
He says that Dexcom has eliminated the use of a shower patch. The needle size has also been reduced, so it should be more comfortable to insert (yay!). Mr. Rasdal claims that Dexcom has listened to their users so features we have asked for will be included. He mentioned that the price is likely to be increased, though the price per day is effectively reduced. (For those of us already getting more than 7 days out of a sensor, it just may end up being more expensive.)
Andy Rasdal also talked about studies that show improved outcomes (over 7 day periods) when using the Dexcom system. This shows a 40% reduction in time spent hypoglycemia, a 33% reduction in hyperglycemia, and a 24% increase in the time spent euglycemic (normal blood sugar levels, also called normoglycemia).
The study looked at folks with less control and found that within a few days they could effectively double the time they spent in euglycemia. These were people for whom it was believed that CGM would not provide any benefits.
The new Dexcom data manager supports downloads of data to the PC for more analysis and for communicating to doctors. I guess we'll see what this means when I can get my hands on it. I still haven't succeeded in cracking the Dexcom data format, and this alone would be a big improvement
Dexcom has 3 peer-reviewed studies published in various journals. During the webcast he referenced a new study on long term outcomes to be published in the June issue of Diabetes Technology and Therapeutics
Dexcom emphasized that this is the second generation of the Dexcom technology with more coming in the future.
Towards the end of the presentation (31 minutes in) he mentioned the new CMS codes for CGM, and the importance of working hard on better insurance reimbursement. He mentioned five letters from Congress that endorsed CGM and looking for better coverage (I wonder whether these could be obtained under Freedom of Information). And that Dexcom has a dedicated reimbursement team, but that reimbursement is still spotty.
Interestingly Andy also talked about the needs of intensive patient monitoring post surgery. This is to move the use of Dexcom technology from just ambulatory to in-hospital use. There is 'compelling clinical evidence' to show intensive management reduced mortality and morbidity by 50%, and not all of these folks (only 13%) had diabetes. I think he mentioned a Dr. Vandenburg who had done these studies.
Dexcom sees this as a large market opportunity. There are over 110,000 critical care beds and Dexcom estimates that over 25% of hospitals have implemented intensive regimes with 12-24 finger sticks per day.And that at $3-$5 per stick, the CGM systems might be more cost effective, as well as less stressful to the patient.
This is also a more focused and effective distribution channel instead of selling to individual patients. That would clearly reduce the cost of sales for Dexcom and presumably increase profitability. Dexcom is also building in the capabilities to interface with any monitoring systems.
They see partnering with other devices makers as being significant in the future. He mentioned not just combining with an insulin pump, but perhaps also with an insulin pen. This would mean several million new users, over the several thousand already using insulin pumps.
My Final Thoughts
I think this will put more competitive pressure on Medtronic Minimed, and may also have implication for the (as yet unapproved) FreeStyle Navigator. I'm excited for the folks at Dexcom, but I'll reserve judgment on the new system until I get one in my hands.
Note: I currently own some shares in Dexcom, I work not to let this ownership influence what I'll say about the company or its products.
I was just thinking about how my Dexcom CGM is more than just something that buzzes annoyingly when my blood sugar is going high or dropping low.
To me it's a bit more like a time machine.
Ever since I first got diabetes I would hear or read about how "you have to control your blood sugar levels or..." something terrible will happen.
But here's the problem. The something terrible doesn't happen immediately.
Let's say I go to a church potluck (always causes eating problems for me) and overeat. My blood sugars go high and stay high for a few hours. It's not like I see this or there's any immediate issues. And no-one, including me, can really tell anything happened. Not by looking at me.
The only immediate problem is some level of drowsiness. Unless the numbers run high for some time, I really won't be able to see any immediate issues. And then, by the time I do see issues with my eyes, or kidneys, or heart, or something else it's almost too late.
But this is where my time machine comes in. When I'm wearing the Dexcom, I can see those highs. And knowing what they're doing to me, I really can see the future.
If I have a day where my blood glucose goes to, say, 230, and it takes me a few hours to get it down, I feel those highs in a very different way. I almost imagine the possible future problems and (for me) it's an encouragement to get things more under control.
Don't get me wrong. Seeing the future is more of a pain than a benefit. When I have days where my numbers don't get above 180, that feels good. But the swings and the long highs are hard to take.
I'm still learning how to use this information for better control. And I'm still learning to accept the (WAY TOO LOUD) alarms the Dexcom gives. (Can you hear me, Dexcom folks).
But I'm also starting to get somewhat better control. My total daily dosage has gone down a little, and there are less profound swings.
I thank God for this small blessing, and I'm looking forward to the next generation of devices that will keep me healthy until something better comes along. (Hint: it's a four letter word, C**e).
Update: (August 19, 2007) I'm now using the latest Dexcom, the Dexcom SEVEN. The software that comes with the Dexcom SEVEN (Data Manager 2) has much better support for statistics and it allows you to export the readings in two different formats. This software also works with existing Dexcom 3 systems. Given this solves the problem for me, I'm not doing any more work in trying to understand their crazy data format!
Still no success getting data from my Dexcom STS CGMS. But my recent challenge post about decoding the Dexcom data format seems to have drawn a lot of attention.
Several people have jumped in to have a try at cracking the problem. I sent some e-mails to Dexcom technical support and customer support about this issue. So far, I've received no response. On June 5th I had a conversation with Dexcom which indicated they aren't about to open up the data even in their new version of the software.
I loaded up another Dexcom R2Downloads data file. From looking carefully at the graph in the Dexcom software it seems that there must be at least four types of records in the data stream. These are:
Start of use. With date (MM/DD/YY) and time (HH:MM:SS) values.
Gap in use. With time (HH:MM:SS) value.
Sensor reading. Glucose value, date (MM/DD/YY) and time (HH:MM) values.
Meter reading. Glucose value, date (MM/DD/YY) and time (HH:MM) values.
You can now find on my site two example data files, plus a hand-captured text file containing the values that are probably at the start of one of these data files.
How You Can Help
Maybe you know something about encoding or encryption. These skills may be enough to crack the problem.
If you can't do this, perhaps you can help in an indirect way. And I'll admit this is a little devious. :-)
If you search on Google for Dexcom my blog comes in around the 15th position in the results. I think I might get more attention from Dexcom if my blog came in as the number 1 search term for Dexcom on Google.
Impossible you say? Well, maybe not.
Here's where you come in. Can you post a blog entry on your blog which points to this blog post, and has Dexcom as the word in the link? Maybe write a note explaining that I'm trying to crack this problem for the Dexcom, highlight the Dexcom word and then add http://www.bernardfarrell.com/blog/2007/05/decoding-dexcom-data-format-update.htm as the hyperlink.
This way I'll get the word out about this challenge, plus Dexcom marketing may wake up and realize that this is important to many folks.
Can you tell I'm a little impatient to get to my data? How do you feel about a system that captures data that's important to you, but that doesn't let you get to it? Am I the only one who feels this strongly about this?
Update June 7th 2007: As of today, many people have linked to this post. When you Google search for Dexcom, this post is now about number 8 in the results, which puts me on the first page of Google results for Dexcom. I'm have still to write a letter to Jorge Valdes, VP Engineering, at Dexcom asking him to release the data format so that we can use it to access our data. First I want to hear what they say on the June 11th conference call.
If you'd like to help me, please post about this issue (setting our data free) and link to this blog entry using the word Dexcom, as I've just done here. Thanks.
Note: I currently own shares in Dexcom, I work not to let this ownership influence what I say about the company or its products.
Readers Challenge: Help me decode the Dexcom data format
I've been using a Dexcom STS continuous glucose monitor system for about a month now.
For day to day use, it's really wonderful. I can see highs before they happen and take the edge off them, and I can also watch much more easily for lows and reduce their impact.
But the software continues to be a major annoyance. Basically all it gives me is two very simplistic graphs of the blood glucose data collected by the Dexcom system.
The Glucose Trend graph shows up to one week of glucose readings from the system.
By choosing a smaller number of days, I can see the readings a little more spread out. For me, this makes it easier to look at the values.
However the software shows no summary statistics, and the only way I can actually see that values is by holding my mouse over them.
The other graph is the Modal Day one, which lets me see a number of days worth of data superimposed over a 24-hour period. This makes it a little easier to see patterns.
Again there is no summary data for the selected time period, and I can only look at one time segment at a time. So if I wanted to see what was happening for the last two weekends, I'd need to produce one report for each weekend and then look from one to the other.
OK. Now this is where I ask for your help. I've sent some e-mails to Dexcom asking for more information on how to get the data out of the system. So far, I've heard nothing back. Maybe one of you format hackers can help me in decoding the actual information itself.
Warning, it's fairly technical below this point. And I'm really hoping that someone can help with this problem.
Using some tools such as the wonderful FileMon from SysInternals, I've finally figured out where the receiver data is being stored on my PC. Trust me when I tell you that this is not easy.
For example, on my system, a lot of information is written by the software to various folders in this location: C:\Documents and Settings\Bernard Farrell\Local Settings\Apps\2.0\TO260ZDW.VE3\JGBRCCZA.X12
But the actual receiver data is written into a number of .R2Download files in this location: C:\Documents and Settings\All Users\Application Data\DexCom\DexCom DM - Consumer\ReceiverData\
For example one of them is named {2E6B7BE9-DA8F-42FA-8337-29404D84A829}.R2Download.
The files contain XML structured data, part of which is the readings themselves in some compressed form.
The data is contained in the DataBaseRecords object in this XML file. And from looking at the Signature object later in the file, it may be encoded using some sha1 approach.
I've uploaded the contents of one data file to my server. If you'd like to have a look at the file and see if you can figure out the data portion, then download the data file from here.
And if you can give me any suggestions as to how to decode this, I'd be thrilled.
The Diabetes Technology Blog is focused on using technology to live life to the full with diabetes. I review new diabetes technology including: blood glucose monitors; continuous glucose monitors; blood sugar meters; diabetes software and living with diabetes.
About Me
Name: Bernard Farrell
Location: Massachusetts, United States
I was born in Ireland and now live in the US.
I have had Type 1 diabetes for over 36 years. I struggle with my blood sugar, the same as most people with diabetes.
I wear a Cozmo 1800 insulin pump and a Dexcom SEVEN Plus CGM to track my blood glucose levels.
I'm blessed by God, and every day brings the possibility of a cure.
I do hope that before Dexcom takes this move they improve the adhesion of the sensors. Mine usually look like they're falling off by day 9 and they rarely last beyond day 11 because they peel off. 
Dexcom's CEO has 
