Tandem Pump AutoSoft 90 Infusion Set Issues

I am a new pumper just starting Tandem t:Slim pump with AutoSoft 90 Infusion Set recently. Notice about 30% chance of high post-meal BGs after a new infusion set at a new site. Finally realized a bent Cannula is the main reason for unsuccessful insulin delivery. The Tandem pump did not display any notification in this event. I have the following observations and speculations:

  1. A bent Cannula should cause a partial blockage of insulin subcutaneous delivery. If insulin is not delivered successfully, where does the insulin flow to, i.e. leaking out or else? If external leaking is not observed, where is it? Since the insulin pump did not notify user, we can assume that pump doesn’t recognize the un-successful delivery. Pump manufacturer should consider build in a suitable sensor. So far, the only way to know a bent Cannula is high BGs after a meal beyond 2 hours. Is there any way to know a bent Cannula in a shorter period of time, say immediately after the completion of a bolus delivery? I haven’t find any answer yet.

  2. Recently, I notice an unsuccessful bolus insulin delivery 3-4 hours after a meal with a new AutoSoft 90 infusion set installation just before the meal. Decide to change the infusion set anyway. While removing the old infusion set, my wife notices that there are liquid droplets (insulin) inside the dome of the infusion set. See the picture below. It is likely that insulin droplets leaked from the Cannula to the dome due to a blockage in the passage. Does anyone observe the same when a Cannula is bent during insertion or a Cannula is clogged with blood?

  3. We now check any droplet appearance in the Cannula dome after each bolus insulin injection, so that we don’t need to wait for 2 to 3 hours of high BGs. It may appear in Day 2 or Day 3. So far, this procedure works. If anyone has different way of knowing a bent Cannula, please share.

  4. Possible problems in the design of the AutoSoft 90 launching device:
    a) un-even force during user pulling the spring resulting in adhesive pad surface not in parallel to the casing, i.e. causing a slightly offset angle during insertion. Is it possible to have a design without the need of pulling spring, such as, the Dexcom G6 launcher design, i.e. the spring is loaded in factory? The tubing may be disconnected at the infusion set end, just like at the cartridge end for easy priming purpose.
    b) highest reflective force resulted from a 90 degree insertion, the strength of a non-metal Cannula material may not be adequate. A better non-metal cannula material is required. There are reports that metal Cannula does not bend.
    c) some type of muscle or blood vessels beneath the infusion site may cause bending or plugging in Cannula
    d) no observation window is available for verification of the integrity of the Cannula after insertion. In this respect, VariSoft may be a better choice.

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I didn’t read much of your post. FYI, if cannulas are giving you issues, try a Tru-Steel set (similar to Sure-T for Medtronic users). No more bent cannulas and more comfortable for many users, than cannula sets which are far larger in diameter.


Gotta second the “try the steel ones!” I used different Teflon infusions sets in the later years of Medtronic/Minimed pump usage. In the beginning we on,y have metal and they were big and hurt so was thrilled to try the Teflon ones.
But when I switched to Tandem I had occlusion issues more than I had ever had. So after talking with my Tandem trainer, she gave me a steel one and it has been smooth sailing ever since. The needle is small. I do feel it like I did in the old days. And the best part, if it gets pulled out (which happened when I was at the Women’s March) I just put it back in and slapped a piece of tape over it. Can’t do that with a Teflon one.
Hope you can get a sample to try it out. Good luck and hope you love the new Tandem IQ like I do!


I’m a new user as well and I use the AutoSoft 90 as well. Thankfully I’ve only had one bent cannula, no alarm as well because it’s not technically occluded. The insulin ended up inside the little dome part which looked just like your picture and I could smell the insulin. I agree that the “launcher” design has much to be desired for.

There are other infusion sets available on the Tandem website.

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Thank @Dave44 and @Sally7 for the comments of using TruSteel Infusion set to prevent cannula bending. Thank @lumi73 for the confirmation of droplets in the little dome. I didn’t smell the insulin in my case. Anyway, I placed an order for mixed TruSteel and VariSoft sets in my next monthly supply and will try them out. I lost my confidence for any “AutoSoft” insertion devices. I am somewhat upset about Tandem and its distributor, Bryam Healthcare, for not advising new patients for the likelihood of a bent cannula during insertion. If I was advised, I would probably choose TruSteel to start with. Who would like to take chance for a possible bent non-metal cannula?

It was time for the infusion site change. I hesitated a little bit, but did it anyway. After AutoSoft 90 insertion, the needle was bent slightly. See the photo below. I suspected that this cannula was probably not good, but did a bolus shot of 5 units anyway and had my wife confirm no droplets in the same little dome. Even though no droplets appear in the dome, I probably will have a very challenging day.

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Well,I sure hope it will be a good day! Let’s hope for a good result on this one. I am so sorry you couldn’t get a sample of the steel one, just to try it.
I have always been an old school kinda person and never had good luck with anything with an auto injection device. I was always a push it in myself kinda person. All infusion sets I have used have been manual insertion. When I got samples of some of the newer ones with the insertion device, I tried and didn’t like the lack of control. Who knows, you maybe one of the few who prefer the manual route.
Good luck with the new sets and good luck today. I’m praying for you to have a wonderful day!

I think commenting in this thread jinxed me yesterday as my cannula came out. Naturally I didn’t have a replacement set with me at the office like I normall do because I switched bags. Guess that’s how it goes sometimes. I’m going to see if I can’t get a sample TruSteel or the longer cannula version of the one I use now.

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I have found it to be user error on my part if I get a bent cannula.
I find that I have done one a couple things wrong.
First is that I didn’t FULLY pull out on the applicator to seat both side locks before insertion.
Second is that I didn’t grip the thing correctly, and I ended up unlocking one side before the other.
Third, I flinch. Happened after a few painful strikes, I flinched and caused it to happen.

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As suspected, my post-meal BG (>250) was much higher than normal post-meal BG (around 200), i.e. the bolus shot was not delivered successfully. I switched the tube connection to the “3 day old” cannula remained at the site, as an emergency backup per comments in other threads, and injected 3 unit bolus shot. The BG continued rising to 275, before dropping to normal after 3 hours. Later on, a bent cannula tip was observed.

I like @Sally7 comments for manual insertion. Thank @Hammer for the details of the infusion set insertion techniques. I will pay more attentions to the details. In my opinion, an infusion set applicator should be designed user friendly for all ages. PULLING the spring out is very challenging, as one needs to hold the applicator base tight. The plastic applicator base shape is distorted and gives a feeling of about “to be breaking”. Why don’t they consider use 4 “ears” instead of “2” to reduce the pulling force, or consider make the spring pre-loaded in the factory? POPPING the infusion set is relatively straight-forward, however, the large applicator base makes it difficult to find a large “flat surface” for insertion. PULLING the metal needle out requires very little force, however, making it STRAIGHT out is relatively challenging because the non-metal cannula is already attached. My procedures to confirm a good AutoSoft 90 infusion set insertion are:

  1. Check the metal needle shape: must be straight and not even a slightly bent.
  2. Confirm no leaking around the adhesive pad area or no droplets in the dome after a bolus shot.
  3. Confirm post-meal BGs in normal range.
  4. Switch tube connection to the “3 day old” infusion site if there is any doubt.
  5. Remove the “3 day old” cannula after confirmation of a good insertion of new cannula.

The autosoft looks an awful lot like the Medtronic Mio, which my daughter has been using for 5 years now. Anyone know if they are the same?

We don’t often get bent canulas when using the mio’s, but I’m wondering if you are trying to insert in muscle, the spring just isn’t strong enough to pierce the muscle, resulting in a bend?

Like I said, we rarely have a problem, like maybe 1 bent canula a year, but she uses them on her abdomen and the backs of her arms, fleshy areas. :slight_smile:

I just had a box of these where 7/10 had bent cannulas. I normally don’t have issues with this style kinking, so I assume that something went wrong during manufacturing. Perhaps you also got a bad box? I called Tandem even though I purchase supplies through Edgepark and they sent me a whole new box. The new box is thankfully working fine thus far.

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In my case, there were approximately 3/7 bad AutoSoft 90 sets. I am waiting for 3 AutoSoft 90 replacement sets from Tandem.

I visited Tandem’s Infusion set webpage several times to determine which AutoSoft cannulas, as compared to AutoSoft 90, have features that can facilitate the insertion and possibly know an abnormal cannula insertion without waiting for 3-4 hours high BGs monitoring after a bolus shot.

AutoSoft XC appears to be the only one has “one-handed insertion” and “visible inspection of the point of insertion”. It seems like this XC set is an improvement over 90 set, which requires 2+ hands insertion; however, no video is available at Tandem site yet.

AutoSoft 30 set is another one with “transparent window at the insertion point”. A kinked non-metal cannula itself may not be visible at the transparent window, however, insulin droplets may be visible if not delivered successfully.

Does anyone have experience of getting useful information from the “visible inspection of the point of insertion” or “transparent window at the insertion point”?

The article “Insulin Infusion Sets Troubleshooting Guide” published by American Association of Diabetes Educators has useful information for new pumpers, as follows:

• Malabsorption: Blood, pain/discomfort, redness, warmth, inflammation, etc. at the site
• Silent Occlusion: Consider dual-port cannula (Does Tandem have this type?) or steel needle cannula.
• Bent Cannula: Use a steel needle infusion set. Tandem’s recommendation for those with a history of bent cannulas.
• Insertion Point Window: Check for a fully inserted cannula and if any skin redness appears.
• Tubing w/Safety Loop: Use medical adhesive tape over the loop to reduce the risk of the tubing or cannula being pulling off.

Tandem’s AutoSoft XC may be a better choice over AutoSoft 90 because of “one-hand insertion” and “visible inspection of the point of insertion”. Unfortunately, there is no video demonstration at Tandem’s website. I may need to use TruSteel due to frequent bent Teflon cannulas.

The link of the article:
Insulin Infusion Sets Troubleshooting Guide

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@waynec2 when I spoke to Tandem a year ago, the only major difference between AutoSoft 90 and XC was the size of the connector release. The XC is a smaller grasp which for most is easier to engage/disengage single handedly. IMHO, after using both and eventually moving to steel sets, my preference was for the XC. Tandem from day one pushed the AutoSoft 90s at me as a new user since it was assumed that I was needle phobic (which I am not). My assumption is that Tandem has decided that most new users are slightly squeamish when it comes to inserting Infusion sets, hence the spring loaded you have minimal control insertion tool.

I was not aware that Bryam sent me a box of AutoSoft XC cannula in the second month supply. I actually used couple of AutoSoft XC cannulas. My prior comments on AutoSoft 90 cannula are applicable to AutoSoft XC cannula. AutoSoft XC and AutoSoft 90 cannulas are almost the same, except for the see-through window at the insertion point. In practice, It is difficult to see whether the cannula is inserted completely, but it may be okay to observe insulin droplets if they do appear. The AutoSoft 90 cannula insertion video at Tandem website is suitable for guiding AutoSoft XC cannula insertion.

I gave up one AutoSoft XC after PULLING up the spring, due to the adhesive pad surface isn’t in a perpendicular position with the applicator base. I have doubt that this guiding needle with Teflon cannula would be inserted correctly without bending the cannula. Apparently, TruSteel cannula is the way to go if you don’t want to take chance of a bent cannula.

Per my Tandem rep, there is one manufacturer that makes most of the infusion sets for all the pump companies. The same products are sold by all the pump companies with minor design changes and under their trade names.

I used Animas pumps for almost 15 years. Their infusion sets (Inset) were identical to the Tandem Autosoft except for the connector at the end of the tubing (luer lock for Animas, proprietary for Tandem). I was disappointed about the difference because I had probably 100 Animas infusion sets I otherwise could have used.

I had very few problems while on the Animas pumps nor so far on the X2. Maybe something to do with the tissue where I use them?

I tried a T-Steel set because it was suggested they would work better when using FIasp with the X2. That didn’t prove to be true for me. I liked them except the tubing is shorter than the 43” length on the Inset/Autosoft that I’ve used for so many years. Otherwise I might have switched.

I have been using MEDTRONIC for many years.

This is my second week on the t slim 2 and while the pro’s are somewhat obvious there are a few serious cons.

The adhesive backing on these sets is too small and doesn’t cover a significant enough area. I just tore a set out taking my sweatshirt off. Those medtronic backings can hold up against even the most stubborn door knobs. Like stopped dead in your tracks and still stuck to your body. I barely even tugged this one and it slipped right out. Someone will say ‘use tape’ and I get that sometimes you gotta do some taping, but I NEVER used tape on the medtron.

Also what are people doing about this awful clip? It has slipped off of my waist more times in one week than my medtronic ever did the entire life of the pump.

My last mini gripe is not being able to see the reservoir. Even if it is just for my own worries, I like to checkout the rez before I set it up to be 100% sure there is no air.

There are some solutions for most of your cons.

There are different sets that have an additional piece of adhesive a few inches away from the set and people say that it works well to keep the set from being ripped of.

The clip itself is generally thought to be poorly designed so most people purchase a different one. There are several pump case companies that have good reviews and Amazon also has options available.

As for the cartridges you might just have to get used to not being able to see your insulin but proper filling technique should keep any issues from bubbles from popping up.

Unfortunately there isn’t a pump currently in existence that suits everyone and that is one reason I’m not on one yet. I will wait until a pump comes along that checks all of my personal boxes before getting one. I am looking forward to the tslim sport though as it just may suit me.

Welcome to the forum!

I agree. For the life of me I don’t know why they don’t address this. If you search the forum you’ll find many other posts about the problem and various things people are doing to address it.

At least for me, the case works well for 2-3 months then the spring loses enough tension that it no longer stays securely on my belt or on the waist line of my pajamas. Two remedies work for me. The simplest is to remove the spring from the case and compress it into it’s original geometry with pliers or a vice. I’ve done this up to five times with the same clip.

I’ve also used 3rd party adhesive clips designed for cell phones. You’ll find plenty of options on Amazon. You can attach to the back of the pump or to the case. I use one from Niteize. It will also wear out eventually but they’re cheap and easy to replace.