Automated insulin delivery (AID) systems are a significant advancement in managing diabetes, particularly for individuals who rely on insulin. Often called an “artificial pancreas” or “closed-loop” system, they mimic some functions of a healthy pancreas. AID systems continuously monitor glucose levels and automatically adjust insulin delivery to maintain blood sugar within a target range, aiming to reduce the daily burden of diabetes management.
Components of an Automated Insulin Delivery System
An automated insulin delivery system relies on three distinct, interconnected components that sense, process, and deliver insulin.
A continuous glucose monitor (CGM) serves as the system’s sensor, typically worn on the body. This device measures glucose levels in the interstitial fluid and wirelessly transmits real-time data, often every few minutes, to other AID components.
An insulin pump is a small, wearable device holding a reservoir of insulin. It delivers insulin into the body through a thin tube called a catheter, which is inserted under the skin. The pump can deliver insulin continuously at a programmed rate and provide larger, on-demand doses.
The control algorithm acts as the “brain” of the AID system. This sophisticated computer program often resides within the insulin pump or on a compatible smartphone. It receives continuous glucose data from the CGM and determines how the insulin pump should adjust insulin delivery.
The Control Algorithm in Action
The automated insulin delivery system operates through a continuous feedback loop. The CGM constantly sends glucose readings to the control algorithm. This algorithm analyzes current levels, considers trends, and predicts future glucose trajectories, then sends instructions to the insulin pump.
A primary automated function is the adjustment of basal insulin. Basal insulin refers to the continuous, background insulin infusion needed to keep blood sugar stable between meals and overnight. The algorithm can automatically increase or decrease this basal rate to prevent glucose levels from rising too high or dropping too low, offering particular benefit during sleep.
Some advanced systems also deliver automated correction boluses, which are small, additional doses of insulin. If the algorithm predicts glucose levels will exceed a predefined high threshold, it can automatically administer a bolus to bring levels back into range. This proactive approach helps to mitigate hyperglycemia.
Despite these automated functions, current AID systems are considered “hybrid closed-loop.” Users must still manually input carbohydrate information for meals. This manual input allows the system to calculate and deliver appropriate mealtime insulin doses, which are typically larger and more immediate than basal adjustments.
Comparison to Traditional Insulin Management
Automated insulin delivery systems offer a different approach to diabetes management compared to older methods, providing more automation and predictive capabilities. This contrasts significantly with the reactive nature often found in traditional insulin therapies.
Multiple Daily Injections (MDI) involve administering insulin manually using syringes or pens several times a day. With MDI, individuals must proactively check their blood glucose levels and then decide on the appropriate insulin dose for meals and corrections. AID systems, by contrast, continuously monitor glucose and automatically adjust basal insulin, reducing the constant manual decision-making and injections.
Traditional insulin pump therapy, sometimes called “open-loop” therapy, delivers insulin through a catheter, similar to AID systems. However, a traditional pump does not automatically adjust insulin delivery based on real-time glucose data from a CGM. The user is responsible for manually programming all basal rates and calculating and delivering all bolus doses for meals and high blood sugar readings. Automated insulin delivery systems “close the loop” by integrating the CGM data with the pump through an algorithm, which then automates many of these adjustments, particularly the fine-tuning of basal insulin delivery.
Available Systems and User Considerations
The landscape of automated insulin delivery systems includes both commercially produced devices and community-developed options.
Commercial AID systems are manufactured by medical device companies and have undergone regulatory approval processes, such as by the U.S. Food and Drug Administration (FDA). These systems typically consist of a specific insulin pump, a compatible CGM, and a pre-programmed algorithm integrated within the pump or a dedicated controller.
In addition to commercial options, there are also community-developed, “do-it-yourself” (DIY) AID systems. These systems are created by individuals with diabetes who combine commercially available components, like certain insulin pumps and CGMs, with open-source algorithms. DIY systems offer greater customization but are not regulated by health authorities and require a higher level of technical knowledge and self-management from the user.
Individuals considering an AID system are typically those with Type 1 diabetes who require daily insulin therapy. A person who is comfortable with technology and understands that continued user involvement is still necessary often finds these systems beneficial. While AID systems automate many tasks, users still need to count carbohydrates for meals and troubleshoot issues, making active engagement a component of successful management.