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What is an Insulin Pump with an Advanced Hybrid Closed-Loop System?

Medically reviewed by Dr. Jordan Pinsker, Vice President & Medical Director, Tandem Diabetes Care.

As the technology around the management of diabetes evolves, so too does the hardware and software that drives that technology.   

There are several ways to manage diabetes, ranging from multiple daily injections to the use of an insulin pump. While the diagnoses of type 1 and type 2 diabetes both revolve around the body’s production (or lack thereof) or use of insulin, there are many differences between the two. People with either type 1 or type 2 diabetes can benefit from the use of an insulin pump with advanced hybrid closed-loop technology.

Read more about insulin pumps and how they can help with diabetes management.

What is a Closed-Loop System? 

A closed-loop system combines a continuous glucose monitoring (CGM) sensor with an insulin pump to automate the delivery of insulin. This closed-loop system is sometimes referred to as an “artificial pancreas” because it aims to replicate how a pancreas would react to rising or falling blood glucose levels. If the blood sugar glucose is rising, the closed-loop system would work to recognize the change and increase insulin delivery. Conversely, if blood sugar levels are falling the system would recognize the trend and reduce and suspend insulin delivery.   

This is accomplished by combining the real-time glucose readings of a CGM with an insulin pump’s predictive algorithm — a mathematical set of rules that give the pump parameters for when to administer or stop insulin delivery. This is called automated insulin dosing.

“Automated insulin dosing technology has completely changed diabetes care,” said Dr. Jordan Pinsker, Vice President and Medical Director at Tandem Diabetes Care. “By automatically adjusting insulin dosing up or down in the background, and in some cases automatically giving discrete bolus doses of insulin, people with diabetes are able to worry less about all the details of diabetes management and at the same time dramatically improve outcomes.”

What is an Advanced Hybrid Closed‑Loop System?

An advanced hybrid closed-loop system combines a predictive algorithm with user control. The fact that the user still interacts with the pump and CGM, and at times needs to instruct the pump to give extra insulin or change settings, is why these systems are called “hybrid.”

These systems have “advanced” features, such as predictive algorithms, that allow them to consider not just CGM values, but also insulin on board (IOB), carbohydrates entered, and even consideration of user settings that help them to automatically adjust insulin doses. 

Some systems, such as the t:slim X2 insulin pump with Control-IQ advanced hybrid closed-loop technology, have predictive algorithms that can adjust basal rates to keep CGM blood glucose levels in a preferred range (70-180 mg/dL). Control-IQ technology can also offer what’s called an automatic correction bolus* to bring glucose into range much more rapidly.

This automatic insulin dosing is the predictive algorithm and insulin pump working in unison with CGM to help minimize the frequent decisions needed to manage type 1 diabetes.

Molly McElwee Malloy, Senior Medical Science Liaison Manager for Tandem Diabetes Care, has spent years working on clinical trials for predictive algorithms. Ms. McElwee Malloy, who is also living with type 1 diabetes, said the advancement of predictive algorithms and closed-loop systems have been game-changers for diabetes management.   

“An advanced hybrid closed-loop system — such as Control-IQ technology on the t:slim X2 insulin pump — has removed the minute-to-minute, decision-making burden of diabetes management,” said Ms. McElwee Malloy. “Sleeping through the night and gaining spontaneity for eating and exercise have been great advancements for me personally.” 

Benefits of an Advanced Hybrid Closed‑Loop System

Using an advanced hybrid closed-loop system offers a number of benefits over other diabetes management methods. For example, an advanced hybrid closed-loop system can:  

  • React to changing glucose levels and adjust insulin doses in the background
  • Bring glucose into range overnight to improve quality and quantity of sleep, minimizing high and low blood sugars that would otherwise require waking up to address 
  • Helps provide reassurance that high blood glucose levels will be addressed with automatic insulin adjustments 
  • Allow the user to decrease time spent on diabetes management by providing peace of mind that glucose is being managed while you do something else 

For example, before advanced hybrid closed-loop systems existed, a lot of planning went into exercise and eating. These activities can now occur more spontaneously because the amount of time needed to prepare for them is greatly reduced. This additionally reduces the burden of management.   

“In my mind, the biggest benefit of using hybrid closed-loop technology has been improved sleep,” said Dr. Pinsker. “Automatic insulin dosing systems excel at bringing down blood sugar overnight and keeping it in a steady range, allowing for a great start to the morning.” 

Control-IQ Technology

What is Control-IQ Technology? 

Control-IQ advanced hybrid closed-loop technology is a powerful predictive algorithm available on the t:slim X2 insulin pump from Tandem Diabetes Care. By predicting glucose levels 30 minutes in advance, Control-IQ technology is able to automatically adjust dosing and increase time in range.* 

Unless otherwise noted, all medical information was provided by Jordan Pinsker, MD, and Molly McElwee Malloy, RN, CDCES of Tandem Diabetes Care, Inc.

* If glucose values are predicted to be above 180 mg/dL, Control-IQ technology calculates a correction bolus using the Personal Profile settings and a target of 110 mg/dL and delivers 60% of that value.

Responsible Use of Control-IQ Technology

Control-IQ technology does not prevent all highs and lows. You must still bolus for meals and actively manage your diabetes. Please visit tandemdiabetes.com/tslimX2-use for more information.

Important Safety Information
RX ONLY. The t:slim X2 pump and Control-IQ technology are intended for single patient use. The t:slim X2 pump and Control-IQ technology are indicated for use with U-100 insulin only. t:slim X2 insulin pump: The t:slim X2 insulin pump with interoperable technology is an alternate controller enabled (ACE) pump that is intended for the subcutaneous delivery of insulin, at set and variable rates, for the management of diabetes mellitus in people requiring insulin. The pump is able to reliably and securely communicate with compatible, digitally connected devices, including automated insulin dosing software, to receive, execute, and confirm commands from these devices. The t:slim X2 pump is indicated for use in individuals six years of age and greater. Control-IQ technology: Control-IQ technology is intended for use with a compatible integrated continuous glucose monitor (iCGM, sold separately) and ACE pump to automatically increase, decrease, and suspend delivery of basal insulin based on iCGM readings and predicted glucose values. It can also deliver correction boluses when the glucose value is predicted to exceed a predefined threshold. Control-IQ technology is intended for the management of Type 1 diabetes mellitus in persons six years of age and greater.

Warning: Control-IQ technology should not be used by anyone under the age of six years old. It should also not be used in patients who require less than 10 units of insulin per day or who weigh less than 55 pounds.

Control-IQ technology is not indicated for use in pregnant women, people on dialysis, or critically ill patients. Do not use Control-IQ technology if using hydroxyurea. Users of the t:slim X2 pump and Control-IQ technology must: use the insulin pump, CGM, and all other system components in accordance with their respective instructions for use; test blood glucose levels as recommended by their healthcare provider; demonstrate adequate carb-counting skills; maintain sufficient diabetes self-care skills; see healthcare provider(s) regularly; and have adequate vision and/or hearing to recognize all functions of the pump, including alerts, alarms, and reminders. The t:slim X2 pump, and the CGM transmitter and sensor must be removed before MRI, CT, or diathermy treatment. Visit tandemdiabetes.com/safetyinfo for additional for additional important safety information.


Reviewed by

Jordan Pinsker, MD

Dr. Jordan Pinsker has served as our Chief Medical Officer since November 2023 after joining the Company as Vice President and Medical Director in April 2021. He is a leading pediatric endocrinologist and prominent thought leader in artificial pancreas research. Dr. Pinsker joined Tandem from Sansum Diabetes Research Institute in Santa Barbara, California, where he served as the Director of Artificial Pancreas Technology since 2018. In his role at Sansum, he was a lead investigator in numerous clinical trials on automated insulin delivery systems, including Basal-IQ technology and Control-IQ technology. Prior to this, he was Chief of Pediatric Endocrinology at Tripler Army Medical Center in Hawaii. Dr. Pinsker served as a physician in the United States Army in both Active Duty and in the California Army National Guard for more than 20 years. He completed a combined seven-year BS/MD program with Union College and Albany Medical College in New York. Dr. Pinsker is board certified in Clinical Informatics, Pediatric Endocrinology, and General Pediatrics. You can read about many of his studies on his Google Scholar page.

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