One of the newest closed-loop insulin pumps on the market stands apart from the crowd. The Beta Bionics iLet ACE insulin pump operates quite differently compared to its competitors — Tandem’s t:slim, Insulet’s Omnipod 5, and Medtronic’s MiniMed 780G.

Approved by the U.S. Food and Drug Administration in May 2023 for children and adults with type 1 diabetes, the iLet “bionic pancreas” promises “diabetes without numbers,” a radically streamlined and simplified approach to blood sugar and insulin management. Partnering with a Dexcom G7 continuous glucose monitor sensor, the iLet promises to handle your insulin dosing automatically, with very little input (and no math) from the user. It’s so radically simple that some members of the T1D community are skeptical — and we hear that some endocrinologists are even hesitant to prescribe the device!

Here’s a breakdown of what makes the iLet ACE insulin pump so different:

The only data you enter is your body weight
No basal rate settings
No insulin-to-carbohydrates ratios
No correction factors
No manual corrections
No manual adjustments to basal
No precise carb counting
Only three bolus options for food: “usual,” “less than usual,” or “more than normal”

The rest is left up to the iLet system to learn your body’s insulin needs with its intensive algorithm. In fact, there’s so little daily patient involvement, the user guide is actually easy to read … because it’s so short!

Diabetes technology has come a long way: Just ask Bernard Farrell, who was diagnosed with type 1 diabetes in 1972. Here, Farrell shares the ups and downs of his experience over the last four months using the iLet ACE with the Dexcom G7.

Waiting for the Bionic Pancreas Since 1972

“I was diagnosed in Ireland,” recalls Farrell, who is 66 years old. “I was using glass syringes with steel needles. You could only test your blood sugar by dropping these tablets into little test tubes with your urine. It would tell you what your blood sugar was six hours ago. I often thought, ‘What is the point of this?’”

Back then, life expectancy with T1D was still a little fuzzy. Farrell recalls his wife asking his doctor, “Will he be around to walk our daughters down the aisle?”

As a father of six, Farrell has watched his children grow up and start families of their own. Despite also losing his hearing to a combination of tinnitus and general aging, being diagnosed with stage 3 kidney disease (which requires no treatment at this time), and juggling adrenal insufficiency, Farrell is living a very full life. 

Farrell has also used nearly every insulin pump on the market. As a retired software developer, he considers himself relatively tech-savvy and always open-minded to new technology. 

Starting the iLet ACE Insulin Pump

“I do a whole lot less thinking about my insulin doses since starting on the iLet,” explains Farrell. “For the most part, if I just announce my meals to the iLet, and stick with the boundaries of what it’s figured out for me, it does a pretty darn good job.” 

But Farrell had a very rough start with the iLet, and he has a few very significant complaints, too — and things he hopes to see Beta Bionics address in the next version of the iLet.

“Those early weeks where the pump is learning your body’s insulin needs were not easy,” says Farrell. “I was all over the place. I woke up one night with paramedics all around my bed.”

During this severe hypoglycemia episode, Farrell lost consciousness and was seizing. His wife called 911 and gave him a dose of intranasal glucagon, Baqsimi, which kicked in by the time the paramedics arrived.

Just days after the severe low blood sugar, Farrell says his blood sugar was very high for most of the day, and it wouldn’t budge.

“You can’t give yourself correction doses with the iLet, so I just had to wait and wait. It was terrible,” says Farrell, who might’ve been experiencing additional insulin resistance from the severe hypoglycemia just days before and the dosage of emergency glucagon.

Farrell says it took almost a month for the iLet to learn his body’s insulin needs and “start behaving” consistently.

Improved Time-in-Range With Less Work

While some might have been daunted by the episode of severe hypoglycemia, Farrell continued using the iLet ACE insulin pump.

“It has absolutely improved my time-in-range, with far less work on my part and far less hypoglycemia,” says Farrell.

Here’s a look at his blood sugars, time-in-range, and body weight, before and after starting the iLet.

September 2023:

A1c: 7.6 percent
Time-in-range: around 55 percent with frequent lows
Weight: 175 pounds

January 2024:

A1c: 6.4 percent
Time-in-range: around 78 percent
Weight: 165 pounds

On the weight loss, Farrell says the iLet has taught him to snack less.

“After so many years on NPH insulin, where you had to eat an exact amount of carbohydrates every three hours, I was still in the habit of eating that way,” says Farrell. Before insulin pumps and rapid-acting insulin existed, people with T1D took NPH and regular insulin — which dictated exactly how much you had to eat on a rigorous schedule.

“With the iLet, I’ve learned how to break from that habit and be more consistent, because it helps the algorithm,” explains Farrell. “I eat more carefully.”

He’s also usually sleeping better, too.

“Overnight, I’m usually flatlined from 10 p.m. to 6 a.m.,” a significant improvement compared with Tandem’s t:slim, which Farrell says never worked well for him.

What Beta Bionics Needs to Address ASAP

While the iLet has won Farrell over, there are still a number of critical technical details he feels Beta Bionics really didn’t prioritize.

“Just two weeks ago, I looked down at my insulin pump and it was hanging open. It had broken,” says Farrell. “I have no recollection of knocking it against anything. But I called Beta Bionics and they overnighted a new pump to me.”

Farrell reluctantly relearned how to manage his blood sugars via multiple daily injections, with Lantus and Fiasp, until his replacement pump arrived.

“When I got the new pump, I called them and asked how to transfer my information to the new pump,” says Farrell. “It had just spent the last three months learning my body’s insulin needs.”

Farrell was shocked when the customer service representative told him there was no way to transfer past data. The new pump and algorithm would have to learn his insulin needs all over again.

“I said, ‘You have got to be kidding me … I have to retrain it all over again?’ That’s just ridiculous. I worked in software my whole career; I know they could prioritize this if they wanted to.”

Fortunately, Farrell found it easier to train the pump this time — taking less than a week before it started to “behave” — and he thinks using Fiasp instead of NovoLog helped.

No Temp Basal Rates? What About Exercise and Sick Days?

Another shortcoming is the inability to set a temporary basal rate for physical activity, sick days, or other times when you know you won’t need as much insulin as usual.

“The only thing you can do when exercising is unhook yourself [from the pump] and hope it all works out,” says Farrell. This is easier said than done: In order to mimic the healthy body’s ability to reduce insulin levels during exercise, people with type 1 diabetes need to adjust their insulin delivery rates as early as two hours ahead of time.

When the snow melts and he returns to bicycling regularly, Farrell anticipates having to eat extra carbohydrates before and during his exercise to counter the excess insulin on board — something people with T1D shouldn’t really have to do in the year 2024 if they can properly reduce basal insulin rates.

“It shouldn’t be that hard to offer a temp basal rate for exercise,” says Farrell, who feels some type of immediate basal intervention should be an option on the iLet. 

Farrell also got COVID in December and subsequently required steroids during his recovery. 

“I run very high when taking steroids. Usually, with the t:slim, I would’ve adjusted my basal rate settings,” says Farrell. “With the iLet, I couldn’t change anything, but my numbers were actually in range 83 percent of the time, with an average of 133 mg/dL.”

Alarms Are Too Quiet

Last of all, Farrell says the alarms are painfully quiet. So quiet that it doesn’t wake him or his wife up during the night — something that would be critical during severe hypoglycemia events like the one he experienced.

To compensate, Farrell purchased a device, the SugarPixel, that vibrates when you’re low, which he puts under his pillow.

“You also can’t hear the difference between high and low,” says Farrell, wishing the alerts were more recognizable. “The Sugar Pixel has been so helpful, I’m actually considering purchasing a second one to keep downstairs.”

A Great Product That Needs Some Improvements

“I’m going to keep using it,” says Farrell, who appreciates the noticeable impact on his A1c, time-in-range, and weight. “But I do feel like it’s a really well-done school project that needs more work.”

“I spend a whole lot less time thinking about diabetes in general,” continues Farrell. “It has trained me to stop snacking to feed possible lows. I’m generally living a more normal life with it.”

“I think this is the way of the future. We’re going to see much more automation in ways we don’t even understand right now,” says Farrell. “I’d really like to see this succeed, but it’s got a number of challenges ahead of it. Both of my oldest friends on insulin pumps want to try it but their endocrinologists won’t prescribe it. It seems like the endos don’t like that they can’t adjust the basal rates and other settings.”

Farrell laughs at the idea of his next appointment with his own endocrinologist. Usually, they spend the entire appointment making tiny adjustments in all of his basal rates, correction factors, and insulin-to-carbohydrate ratios.

“There’s nothing they can do now,” laughs Farrell. “He’ll probably just tell me to keep doing what I’m doing and that’s that. In the meantime, I plan to use this until the next generation is on the market.”