Struggling with control


OMG. I remember, back in the day, all the pump vendors said their pumps were water proof. (One pump I owned actually used water proof in their sales brochure. Something about “I lost my pump while canoeing. But we found it the next day. I changed out the battery and it worked fine!” or something like that.)

I ruined so many pumps by actually believing them. Then they quit saying they were water proof. Now they’ve gone back to saying it again, but I don’t believe it.


It would be hard to find something which is truly waterproof. My way of thinking is:
I don’t care.

What do I care about?
Is the manufacturer confident enough in the ability of their product to withstand water such that the manufacture will replace the device under warranty at no additional cost should the device suffer water damage.

If the answer is no then I am super careful not to get it wet. Such as the Dexcom Receiver. I am careful to not allow it to get wet even a little bit.

If the answer is yes such as with the Tandem t:slim X2 pump then I don’t worry in the slightest about water. For all practical considerations (which for us does NOT include scuba diving but DOES include Kayaking) we consider the Tandem to be waterproof. Tandem customer support has assured me they will replace the unit for any water damage and will not grill me regarding how long it was under water or how deep it went.

NOTE: Tandem support assumes the unit was not deliberately opened by the end user. The manual specifically states:

DO NOT open or attempt to repair your System. The System is a sealed device that should be opened and repaired only by Tandem Diabetes Care, Inc. Modification could result in a safety hazard. If your System seal is broken, the System is no longer watertight and the warranty is voided

In terms of what Tandem actually claims for their pump, Tandem states the pump is watertight to IPX7 specifications and further clarifies they specifically claim the pump is watertight to a depth of 3 feet for up to 30 minutes. The manual has further information on this topic if anybody is interested in the details.


With my previous Minimed, I found a waterproof bag that I would place my insulin pump in before anything that would seriously threaten the water resistance of the pump.

It was made by AquaPac. they marketed it at the time for microphones. It worked fine for my MiniMed 530, but was not big enough for the 630.

They now sell one specifically marketed for insulin pumps. It should fit the 630 and 670. They list the dimensions on the link.

That thing is awesome. I’ve used it while kayaking and swimming in the ocean, while climbing a waterfall in Jamaica, and while playing in the pool at my in-laws. Never once was there a hint of moisture inside the bag at the end of the day.

I highly recommend their products if you’re going to be in the water with a pump.


In our family my wife got the first supposedly water-tight Medtronic pump, the 511. Shortly after she got it we got a letter stating that it was not actually watertight. My next pump that was similar was the 515 so by that time I knew that Medtronic had overstated the capabilities of their pumps with regards to water resistance so I try to keep it dry. However that failed when I overturn to jet ski in Mission Bay. The pump failed a few days later. At least it didn’t quit while I was on vacation


I don’t know why they can’t make the innards of the receivers and other electronics water phobic. There have been chemicals on the market for years that can do that


Thanks for the Aquapac link! I work outdoors, even in the rain. Can’t wait to get the Aquapac I just ordered. :smiley:


@CaM2, How right you are. I believe an excellent sensor is one of the prerequisites for a closed loop system. Medtronic likes to overstate their capabilities. That’s a reason I stopped doing business with them. Get a Dexcom. At least you got a fighting chance, then. Trust is dead for medtronic. The thrill is gone. Only ONE time do I need to see someone putting my life at risk for small, personal gain. (P.S. BB King was a diabetic.)


Here’s a Nova special that deals with ideas behind closed loop systems (indirectly). Its free to anyone temporarily.

When you are considering if a closed loop system is a good fit, you might be asking, “Are my calculations better than theirs?” Depends on the individual. But, I still believe that all of you are quite good and they are not very good, yet.


In the narrow case of my metabolism, I think I can make just as good a decision as a closed loop algorithm. Where I fail when compared with a closed loop system is that I am not up to the job of making a decision every five minutes of every day.

I enjoyed the video, very entertaining.


@Terry4, You’ve always had pretty flatline data. Do you find that the system is good at anticipating those deviations 2 or 4 hours out?

On another note, I see the diabetes unconvention isn’t running this year. Bummer. You should get people on board the following year, if you have an interest in going. Would you attend again? Fun?

I’m scare to death of your system, but if we are both still alive in 10 years, I vow that I will try it out. Ten years…2028.


@mohe0001, please forgive my ignorance, but what was (is) this convention?


A bunch of the guys went there a few years ago. They called it off this year to re-evaluate their mission, or something like that. They are trying to improve it. I’ll see if anybody posted about it, but you know how it goes, “what happens in Vegas, Stays in Vegas.”


No, but there are other meetings that may interest some people here.

connecT1D runs a weekend retreat for T1Ds in the Seattle area. This year it is June 23-24. I attended last year and it was fun.

Another T1D retreat will take place in San Diego August 17-19, organized by TCOYD, but dedicated to T1Ds. TCOYD or Taking Control of Your Diabetes conducts one day workshops for all diabetics and their loved ones all over the country.

The Diabetes Unconference included both T2Ds and T1Ds and their loved ones. They were great meetings focused on the psycho-social aspects of diabetes. The conferences were organized by Christel Marchand Aprigliano, an amazing and energetic woman who now devotes her passion to diabetes advocacy at DPAC.

I have no relationship with any of these meetings or organizations other than as an attendee.


When I first heard about automated insulin delivery that modulated basal delivery, I was skeptical. I am impressed, however, with how effective it can be. You do still need to “announce” meals; meal boluses are not automated. There are limits to what it can do but, yes, it can be effective changing the BG trajectory 2+ hours out.

I feel my personal safety and risk is greater when not using my system. Living with diabetes can be dangerous!


In 10 years, Terry, if they somebody makes some more progress down one of the avenues they are looking at, I will try. There are a number of very promising avenues. The math has progressed rapidly in the past ten years, so there’s no telling what it will be in another ten. Thanks for guinea pigging. :smile: If I were them, and I was interviewing guinea pigs, I would want you.


The success of this system will heavily rely on the accuracy of the CGM sensor. Are the sensors now really that reliable? What if you get the odd faulty sensor? Does the system know this too? I am now on the Vibe and is forced to switch to the MM 630g for free. After that warranty expires, I can switch to the 670g. That will be awesome! Good input as usual my GURU @Terry4. Thanks.


@mohe0001 @Terry4, Thank you both for the info. TCOYD I have done and I am going back again this year. I will have to look into the others. Thanks again for the info!!


@arpida_seru, I think Terry4 is using a Dexcom CGM in his closed loop setup. I recently read his review of the system.


I think the Dexcom sensors are reliable enough. I’m lucky to enjoy relatively stable BGs with fairly low variability, so that can tolerate some CGM data inaccuracy. I’ve used Loop for 16 months now.

In the year or two leading up to the debut of automated insulin dosing systems, I also felt that current CGM systems needed to get better before being used around the clock to make insulin dosing decisions. I thought that the insulin needed faster onset and peak to make a reliable system. I’ve changed my mind on both accounts, however. Current Dexcom CGM accuracy paired with current insulin action times can yield a useable system. It’s not perfect but it does give me better control with less burden than a pump/CGM combo without a controlling app.


@Terry4, can you please direct me to this closed loop discussion. TY