{"id":4864,"date":"2024-07-20T10:16:22","date_gmt":"2024-07-20T09:16:22","guid":{"rendered":"https:\/\/www.springboard.pro\/?p=4864"},"modified":"2026-09-01T18:12:57","modified_gmt":"2026-09-01T18:12:57","slug":"closing-the-loop-the-latest-on-artificial-pancreases","status":"publish","type":"blog","link":"https:\/\/www.sanner-group.com\/insights\/blog\/closing-the-loop-the-latest-on-artificial-pancreases\/","title":{"rendered":"Closing the Loop: The Latest on Artificial Pancreases"},"content":{"rendered":"\n
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Closed-loop insulin delivery systems, also known as artificial pancreas systems, are currently in an exciting phase of technological innovation and transformation, and look set to transform the management of diabetes for the future. These innovations are driven by enhancements in sensing and delivery technology, promising clinical trial results, and new regulatory approvals.<\/p>\n

The development and provision of these systems is currently focused on people with Type 1 Diabetes (T1D). People with T1D have an immune system that attacks the \u03b2 cells in the pancreas which create insulin, a hormone which enables the transport of that glucose from the bloodstream to the rest of the body. Most of the insulin produced by a healthy \u03b2 cell is a reaction to the current level of glucose in the bloodstream, however some is even produced by the body during chewing in preparation for a blood sugar spike.1<\/sup><\/p>\n

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Figure 1: Insulin levels in the blood of a healthy human, showing the sensitivity required to maintain a healthy blood sugar level over the course of the day.2<\/span><\/strong><\/p>\n

People with T1D must inject insulin to manage their blood glucose levels over the course of the day. With a manual system, calculation of the required insulin dose can be a complex process, requiring patients to constantly monitor glucose levels and use that information to plan and execute calculations at specific times.2<\/sup> The effect of a certain dose of insulin even has its own day-to-day variability, which is difficult to predict. Most people with T1D are therefore not able to achieve their recommended glycemic targets.3<\/sup><\/p>\n

Artificial pancreas systems aim to bring management of T1D into the digital era. The essential components are a continuous glucose monitor (CGM), an insulin pump and a control algorithm. Most systems are known as \u2018hybrid\u2019, meaning that even though insulin rate is adjusted automatically, users still have some interaction with the system, for example counting and entering mealtime carbohydrates.4<\/sup><\/p>\n

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Figure 2: The key components of an artificial pancreas system.6<\/span><\/strong><\/p>\n

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A SPIKE IN PRECISION<\/u><\/strong><\/p>\n

CGMs measure glucose levels in the interstitial fluid between cells in the abdomen or back of the upper arm, normally via an enzymatic reaction. There is an inherent delay of approximately 10 minutes5<\/sup> in the reading when measuring blood glucose in this way, which affects the accuracy of the reading and thus the performance of the control algorithm.<\/p>\n

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Figure 3: Improvements in CGM MARD since 1990.9<\/span><\/strong><\/p>\n

 <\/p>\n\n\n\n\n\n
<\/td>\nFDA approval (year)<\/td>\nCE mark (year)<\/td>\nMARD (%)<\/td>\nWarm up time (hours)<\/td>\nService life (days)<\/td>\n<\/tr>\n
Abbott FreeStyle Libre 3<\/td>\n2022<\/td>\n2022<\/td>\n7.9<\/td>\n1<\/td>\n14<\/td>\n<\/tr>\n
Dexcom G7<\/td>\n2022<\/td>\n2020<\/td>\n8.2<\/td>\n0.5<\/td>\n10<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

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Table 1 \u2013 Technical details of the most recently approved CGMs<\/p>\n

 <\/p>\n

As shown in Table 1 above, the newest CGMs can achieve a mean absolute relative difference (MARD) of 8% when compared to a calibrated reference, report glucose levels every minute, and do not require any calibration by the user by way of a fingerstick reading. The impressive accuracy of current monitors is the result of year-on-year performance improvements as can be seen in Figure 1, where an MARD of <10% is considered accurate enough for insulin dose calculations.6<\/sup> It is currently unclear whether the accuracy of new sensors will continue to improve or begin to flatten out as we approach the limit of the technology.<\/p>\n

Further development work in this area is also ongoing to ensure that the accuracy of the CGM is maintained over a range of use cases. For example, compression of the device when sleeping and long periods of aerobic exercise have been shown to produce erroneous readings. There are also efforts to reduce the effects of various interfering substances such as ascorbic acid, hydroxyurea, and others yet to be identified.7<\/sup><\/p>\n

SMART PUMPS AND APPS<\/u><\/strong><\/p>\n

The control algorithm can either be integrated into the pump itself or located on a separate device, which can even be a smartphone. The safety of the control system is paramount, as delivering too much insulin can cause hypoglycemia which can quickly become life threatening if untreated.<\/p>\n

The three main types of control algorithms used in approved systems are:<\/p>\n