FDA Clears twiist Automated Insulin Delivery System
By April Hopcroft
The twiist AID system is the first insulin pump to integrate with Tidepool Loop. Approved for people with type 1 diabetes ages 6 and up, the twiist AID system with Tidepool Loop offers precise microdosing, the option to set a target as low as 87 mg/dL, and bolusing based on different food types.
In the latest victory for type 1 diabetes management, the FDA cleared the twiist automated insulin delivery (AID) system with the Deka insulin pump, the first pump to precisely measure each dose of insulin delivered. The twiist AID system will be sold by Sequel Med Tech, a company focused on improving the health and life of people with diabetes.
Specifically, the twiist AID system measures both the volume (amount) and flow (speed) of each micro-dose of insulin. This allows for more personalization of insulin dosing, which could allow for more precise glycemic control and better health outcomes.
The twiist AID system is also the first FDA approved AID system that can be directly controlled by an Apple Watch.
“I am excited to see another AID pump as an option for our patients as there is no one choice for people with diabetes,” said Dr. Natalie Bellini, clinical assistant professor of medicine at Case Western Reserve University in Ohio.
What does the twiist AID system consist of?
All AID systems consist of three parts: an insulin delivery device, insulin delivery algorithm, and a continuous glucose monitor (CGM). The twiist AID system includes the following components:
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The Deka insulin pump, which is approved for use with the rapid-acting insulin Humalog. The reservoir holds 300 units and is disposable, while the rest of the pump can be reused for up to three years.
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The Tidepool Loop algorithm, which automatically adjusts insulin delivery based on CGM readings and includes several innovative features – more on this below.
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A compatible CGM sensor.
The Deka insulin pump is the only pump to directly measure the volume and flow of insulin, whereas other insulin pumps rely on proxies such as pressure sensors or the number of clicks and turns.
Specifically, the Deka pump takes four measurements to precisely calculate the amount of insulin delivered with each micro-dose: a first measurement is taken when the chamber is empty, another when it is filled with insulin, a third to confirm the filled amount, and a final measure once the insulin dose is delivered. The difference between the second measurement (full chamber) and the final measurement (empty chamber) is the actual dose delivered.
“The twiist AID system reimagines how insulin is measured and delivered for more personalization with a simpler design,” said Dean Kamen, president and founder of Deka, who is also well known for developing the first insulin pumps and the Segway.
“I believe the twiist AID system will set a new standard for precise, dependable insulin delivery going forward,” Kamen said.
Key features of the Tidepool loop algorithm
Tidepool Loop is the first FDA-approved technology to have begun as a patient-led project, rather than by diabetes technology companies. This means the technology was developed by people with diabetes, for people with diabetes.
Tidepool Loop is unique because it enables users to build their own AID system by combining a wide variety of CGM sensors and insulin delivery devices. By contrast, people seeking to use open source or do-it-yourself (DIY) AID systems have a much more limited number of compatible insulin pumps to choose from – just Omnipod Dash and older Medtronic pumps.
Some may worry that using the Tidepool algorithm as part of the twiist AID system requires users to be tech-savvy.
“You don't need to be an 'uber' tech user to take advantage of the system,” said Jeanne Jacoby, senior director of medical affairs at Sequel. “Like other AID systems, the system will work best when a user announces their meals by entering carbs. Day-to-day use of the system is not complicated.”
Lower targets for better time in range
With the Tidepool Loop algorithm, people who use the twiist AID system can set targets as low as 87 mg/dL. This is considerably lower than the standard target of 110 mg/dL that is pre-specified by other insulin pump companies. Setting a lower target glucose is key to achieving tighter glycemic control and increasing time in tight range.
A bounty of bolus options
Bellini highlighted the ability to distinguish the type of carbs that will be consumed as a key aspect of the Tidepool Loop algorithm. For example, there are settings such as ‘lollipop’ for rapid-acting carbs, ‘taco’ for moderate carb/fat/protein foods, and ‘pizza’ for higher fat/protein carbs. These settings change the delivery of the bolus, which is important since not all carbs behave the same.
Additionally, the system includes a “pre-meal preset” mode to increase insulin delivery before meals. This helps to reduce post-meal blood sugar spikes and also minimizes the risk of hypoglycemia due to pre-meal bolusing.
The Tidepool Loop algorithm also allows users to adjust carb entries proactively (before eating) and retroactively (after eating). This feature addresses the unpredictability of real life with diabetes – sometimes, you eat more or less than you intended.
Microdosing for more precise glycemic control
The twiist AID system also allows for microdosing, meaning that it can deliver insulin in amounts less than 1 unit for more precise glycemic control.
As glucose levels rise, the system will deliver an exact number of insulin, such as 0.3 units or 1.2 units, to bring you to target based on your personal insulin sensitivity factor – how much one unit of insulin is expected to lower blood sugar. Historically, insulin pumps delivered doses in single units only, though newer systems like Tandem’s t:slim X2, Medtronic’s Minimed 780G, and Insulet’s Omnipod 5 also allow for microdosing.
What’s next?
Although information is not yet available regarding the launch date of twiist, Sequel’s co-founder and CEO Dr. Alan Lotvin noted that the company plans to make the device available in pharmacies with a pay-as-you-go model for greater access and affordability.
According to Christopher Gilbert, VP of Marketing at Sequel, offering insulin delivery systems in pharmacies is often smoother for both patients and healthcare providers, and usually only involves a co-payment. Sequel’s goals are to remove cost as a barrier for people looking to start on an AID system and to allow people with diabetes to get started quickly, without making a long-term commitment, Gilbert said.
In contrast, commercial insulin pumps typically involve a four to five-year commitment and must be purchased through Durable Medical Equipment suppliers (i.e., Advanced Diabetes Supply, Byram Healthcare).
Ultimately, the system marks a step forward for AID by allowing users greater choice and customization. With Tidepool Loop technology, users can choose from a variety of compatible CGMs and also have the option to set lower targets, choose different bolus levels, and adjust carbs after eating.
“The key takeaway is that it’s a holistic solution to provide people with diabetes a simple, affordable way to get started and a technology that can be flexible and personalized to meet individual needs,” Gilbert said.
This approval marks Tidepool’s first partner with an FDA-cleared insulin pump, a highly anticipated milestone since Tidepool Loop was first approved in June 2023.
“It's all exciting. I think a main point here is that the open source community built the Loop algorithm years ago, and now it's approved and with an innovative pump partner," said Diane Scherer, diaTribe's development director who lives with type 1 diabetes and uses Open Source Loop. "The community is empowered to make change and companies like Sequel and Tidepool are using their expertise to be a part of the future.”
Learn more about automated insulin delivery:
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Here's Why I'm Eager but Cautious About Trying New Diabetes Technology
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What We Wish You Knew and Why: Open-Source DIY AID, Access, and Stigma
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AID Systems Hit Impressive Time in Range Targets, Large Studies Show
Image credit: Sequel Med Tech
