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type1.science

twiist (Sequel)

Sequel Med Tech (hardware by DEKA Research & Development)

A round, ultralight tubed pump (under 2 oz / ~57 g) holding a 300-unit cassette swapped every ~3 days. Its standout is iiSure acoustic sensing, which physically measures the volume and flow of every micro-dose of insulin — catching blockages up to 9x faster than other AID systems. It runs the FDA-cleared Tidepool Loop algorithm on-system, is fully controllable (including bolus) from an iPhone and Apple Watch, and works with FreeStyle Libre 3 Plus and Eversense 365 CGMs. FDA-cleared for ages 6+ and fully launched in the US via a low-cost pharmacy channel.

Available nowRegulator-approvedpumptubeddurablephone-control

The scorecard

Interoperability72

Runs the FDA-cleared, interoperable Tidepool Loop algorithm and works with Libre 3 Plus and Eversense 365 (Dexcom in development), and Diabeloop's DBLG2 is cleared as a second on-system algorithm — but it remains a closed commercial system, not open to DIY.

Reliability78

iiSure acoustic sensing directly measures delivered insulin volume and flags occlusions up to 9x faster than rival AID systems; precision is strong, but it is a new 2024-cleared platform with a short real-world track record versus established pumps. The clinical evidence base is growing — a 13-week, 307-person study (in type 2 diabetes, an investigational use) reported no severe hypoglycemia — but that is still short-horizon data outside the type 1 indication.[1]

Form factor58

Round and remarkably light (under 2 oz / ~57 g, about the size of an Oreo), but still a tubed pump worn on the hip or in a pocket, so it trades discretion against true patch pumps.

Phone control90

The first AID system fully controllable — including bolusing — from both an iPhone and an Apple Watch, with one-button boluses, alongside on-pump control.

Capacity76

300-unit cassette matches the largest tubed reservoirs, swapped about every 3 days; rechargeable batteries are hot-swapped at each cassette change so the system runs continuously.

Access & cost70

Fully launched US-wide through the pharmacy channel on a low-commitment, low-cost plan with no long-term contract, but currently US-only and iPhone-only.

The full picture

The twiist is a tubed insulin pump with an unusual round shape and an even more unusual party trick: it is the first delivery system that physically measures the insulin it sends, rather than just assuming the motor pushed the expected amount.1 It is made by Sequel Med Tech, with the hardware engineered by Dean Kamen's DEKA Research — the firm whose founder built the first portable insulin pump in the 1970s.2

Form factor and wear. It is a small round disc — about the size of an Oreo — weighing under 2 oz (~57 g), which Sequel bills as the lightest pump of its capacity.3 It is tubed (worn on the hip or tucked in a pocket) rather than a stick-on patch, though Sequel says body-worn adhesive options are in development.4 It is rated water-resistant to about 12 feet for 1 hour.5

Reservoir and infusion set. A bladder-style "cassette" holds up to 300 units of insulin — matching the largest tubed reservoirs — and is changed roughly every 3 days.6 Power comes from small rechargeable lithium-ion batteries that you hot-swap at each cassette change; the starter kit ships with four batteries and two chargers, so the pump runs continuously.65 It connects to standard infusion sets such as the Smiths Medical Cleo 90, Unomedical Comfort, and Medtronic MiniMed Silhouette/Quick-Set.7

Occlusion detection. This is the headline feature, branded iiSure: an acoustic sensor directly measures the volume and flow of every micro-dose through four delivery checkpoints, so a blocked line or under-delivery is caught — Sequel says — up to 9x faster than other AID systems.46 That is a genuinely different safety model from pumps that infer delivery from motor turns.

Algorithm, CGM, and phone bolusing. The twiist runs the FDA-cleared Tidepool Loop algorithm on-system, which adjusts insulin every 5 minutes against a 6-hour glucose prediction.14 Tidepool Loop is itself notable: it grew out of the DIY Loop community and in 2023 became the first open-source-derived automated-insulin algorithm ever cleared by the FDA, as an interoperable controller.8 The pump pairs with the Abbott FreeStyle Libre 3 Plus and the implantable Senseonics Eversense 365 CGMs (Dexcom support is in development).45 Uniquely, it is fully controllable — including delivering a bolus — from an iPhone and an Apple Watch, with optional one-button boluses, as well as from the pump itself; an iPhone is currently required (no standalone receiver).6

Access and cost. twiist is FDA-cleared for people 6 and older with type 1 diabetes.1 After a 2024 clearance and controlled rollout, Sequel fully launched it across the US on March 9, 2026, distributing through the pharmacy channel on a low-commitment, low-cost plan with no long-term contract.2 It is currently US-only.

Type 2 diabetes data — investigational, not an approved indication. At the ADA 2026 Scientific Sessions in June, Sequel presented a 13-week study run at 30 US sites in 307 adults with insulin-treated type 2 diabetes (93% completed; mean age 58; 26% Black, 13% Hispanic). Average HbA1c fell by 0.7% from a baseline of 8.1%, and time in range 70–180 mg/dL (3.9–10.0 mmol/L) rose from 57% to 73% — about four extra hours a day in range — while time below 70 mg/dL (3.9 mmol/L) fell from 0.66% to 0.36%. There were no severe hypoglycemia events, and the single case of diabetic ketoacidosis was adjudicated as unrelated to the device.9 Two cautions matter here. This is a conference presentation reported in the trade press, not a peer-reviewed publication; and twiist is cleared only for type 1 diabetes — the type 2 indication is investigational, with no FDA submission or clearance announced. For people with T1D the relevance is indirect: it is more evidence that the hardware and the Tidepool Loop algorithm behave safely across a larger and more diverse group of users.

What's coming. Sequel is building the twiist into a multi-algorithm, multi-sensor platform. Diabeloop's self-learning DBLG2 algorithm was FDA-cleared in December 2025 as a second on-system option (US launch targeted for 2027), making twiist the first AID system to offer a choice of dosing algorithms — these are ranked separately on this site.10 Sequel has also partnered with Abbott on a future dual glucose-ketone Libre sensor to add early ketone detection, and with Senseonics to integrate longer-wear implantable CGMs.11

References

  1. Sequel Med Tech. Sequel's twiist Automated Insulin Delivery System Receives FDA 510(k) Clearance. GlobeNewswire (2024). https://www.globenewswire.com/news-release/2024/03/18/2847675/0/en/Sequel-s-twiist-Automated-Insulin-Delivery-System-Receives-FDA-510-k-Clearance.html ↩ ↩2 ↩3

  2. Buckley S. Sequel fully launches twiist automated insulin pump in US. Drug Delivery Business News (2026). https://www.drugdeliverybusiness.com/sequel-fully-launches-twiist-pump-us/ ↩ ↩2

  3. Sequel's twiist Automated Insulin Delivery System Receives FDA 510(k) Clearance. BioSpace (2024). https://www.biospace.com/sequel-s-twiist-automated-insulin-delivery-system-receives-fda-510-k-clearance ↩

  4. Sequel Med Tech. What is twiist — product overview. twiist.com (2026). https://www.twiist.com/what-is-twiist ↩ ↩2 ↩3 ↩4

  5. American Diabetes Association. twiist — insulin pump specifications. ADA Consumer Guide (2026). https://consumerguide.diabetes.org/products/insulin-pumps/twiist ↩ ↩2 ↩3

  6. Sequel Med Tech. twiist Frequently Asked Questions (reservoir, batteries, CGM, bolusing). twiist.com (2026). https://www.twiist.com/faq ↩ ↩2 ↩3 ↩4

  7. twiist Automated Insulin Delivery (AID) System review — specifications. Diabetesnet.com (2026). https://www.diabetesnet.com/diabetes-technology/automated-insulin-delivery-systems/twiist-automated-insulin-delivery-aid-system/ ↩

  8. Braune K, Hussain S, Lal R. The First Regulatory Clearance of an Open-Source Automated Insulin Delivery Algorithm. Journal of Diabetes Science and Technology (2023). https://pmc.ncbi.nlm.nih.gov/articles/PMC10563523/ ↩

  9. Sequel Med Tech data supports twiist pump in type 2 diabetes — 13-week, 307-patient study presented at the ADA 2026 Scientific Sessions; the type 2 indication remains investigational. Drug Delivery Business News (8 June 2026). https://www.drugdeliverybusiness.com/sequel-ada-2026-twiist-type-2-diabetes/ ↩

  10. Buckley S. Sequel, Diabeloop to integrate insulin delivery algorithm into twiist. Drug Delivery Business News (2026). https://www.drugdeliverybusiness.com/sequel-diabeloop-insulin-delivery-algorithm-twiist/ ↩

  11. Buckley S. Sequel to pair twiist with Abbott's future dual glucose-ketone sensor. Drug Delivery Business News (2025). https://www.drugdeliverybusiness.com/sequel-medtech-twiist-abbott-dual-sensor/ ↩

What's next for this

  • →Type 2 diabetes indication — 13-week, 307-person study presented at ADA 2026 (HbA1c down 0.7%, time in range 57% to 73%, no severe hypoglycemia). Still investigational; no FDA submission or clearance announced. · not yet announced
  • →Diabeloop DBLG2 self-learning algorithm cleared Dec 2025 as a second on-system algorithm choice · US launch targeted 2027
  • →Partnership with Abbott on a future dual glucose-ketone Libre sensor for early ketone detection
  • →Dexcom CGM support · in development
  • →Body-worn adhesive (tubeless-style) options · in development

Sources

  1. [1]Sequel Med Tech data supports twiist pump in type 2 diabetes (13-week, 307-patient study presented at ADA 2026) · news · 2026-06-08 — Trade-press report of data presented at the ADA 2026 Scientific Sessions. The type 2 diabetes indication remains investigational — not FDA-cleared.