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Artificial pancreas: past, present, future.

Cobelli C, Renard E, Kovatchev B - Diabetes (2011)

View Article: PubMed Central - PubMed

Affiliation: Department of Information Engineering, University of Padova, Padova, Italy. cobelli@dei.unipd.it

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The artificial pancreas (AP), known as closed-loop control of blood glucose in diabetes, is a system combining a glucose sensor, a control algorithm, and an insulin infusion device... AP developments can be traced back 50 years to when the possibility for external blood glucose regulation was established by studies in individuals with type 1 diabetes using intravenous glucose measurement and infusion of insulin and glucose... After the pioneering work by Kadish in 1964, expectations for effectively closing the loop were inspired by the nearly simultaneous work of five teams reporting closed-loop control results between 1974 and 1978: Albisser et al., Pfeiffer et al., Mirouze et al., Kraegen et al., and Shichiri et al.... In all early intravenous and intraperitoneal AP systems, the closed-loop control algorithms belonged to a class known as proportional-derivative controllers, which used blood glucose values and blood glucose rate of change in a relatively straightforward calculation of insulin dose... In September 2006, the Juvenile Diabetes Research Foundation International (JDRF) initiated the Artificial Pancreas Project and funded a consortium of centers to carry out closed-loop control research... So far, encouraging results have been reported by several centers... Two notable achievements were the acceptance by the Food and Drug Administration of the University of Virginia–University of Padova type 1 diabetes simulator as a substitute to animal trials in the preclinical testing of closed-loop control strategies, and the design by a team from the University of California Santa Barbara and the Sansum Diabetes Research Institute of a communication platform allowing the automated transfer of data between CGM, control algorithm, and insulin pump... These first devices had limited performance, particularly in the hypoglycemic range... Since then, significant progress has been made toward versatile and reliable CGM; a number of studies have documented its benefits and charted guidelines for its clinical use... Moreover, with subcutaneous insulin delivery the lost physiological role of the liver in modulating peripheral insulin levels results in higher peripheral insulinemia... Whether such a reduced hepatic insulinization impairs the control of hepatic glucose output significantly is still unclear... The control layers work on different time scales... At the bottom, the fastest layer is in charge of safety requirements... Table 1 summarizes the principal components of a closed-loop system, including the CGM, the insulin infusion device, the control algorithm and the associated human factors, and lists the areas that need further development before the ambulatory AP becomes a reality.

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Block diagram of closed-loop glucose control. Three major delays are indicated: insulin absorption (regular and ultrafast insulin), insulin action on peripheral tissues and on the liver, and sensing in the interstitium.
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Figure 3: Block diagram of closed-loop glucose control. Three major delays are indicated: insulin absorption (regular and ultrafast insulin), insulin action on peripheral tissues and on the liver, and sensing in the interstitium.

Mentions: Despite important developments in sensor and pump technology, the AP must cope with the delays and inaccuracies in both glucose sensing and insulin delivery described in the previous sections. This is particularly difficult when a system disturbance, e.g., a meal, occurs and triggers a rapid glucose rise that is substantially faster than the time needed for insulin absorption and action (Fig. 3).


Artificial pancreas: past, present, future.

Cobelli C, Renard E, Kovatchev B - Diabetes (2011)

Block diagram of closed-loop glucose control. Three major delays are indicated: insulin absorption (regular and ultrafast insulin), insulin action on peripheral tissues and on the liver, and sensing in the interstitium.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3198099&req=5

Figure 3: Block diagram of closed-loop glucose control. Three major delays are indicated: insulin absorption (regular and ultrafast insulin), insulin action on peripheral tissues and on the liver, and sensing in the interstitium.
Mentions: Despite important developments in sensor and pump technology, the AP must cope with the delays and inaccuracies in both glucose sensing and insulin delivery described in the previous sections. This is particularly difficult when a system disturbance, e.g., a meal, occurs and triggers a rapid glucose rise that is substantially faster than the time needed for insulin absorption and action (Fig. 3).

View Article: PubMed Central - PubMed

Affiliation: Department of Information Engineering, University of Padova, Padova, Italy. cobelli@dei.unipd.it

AUTOMATICALLY GENERATED EXCERPT
Please rate it.

The artificial pancreas (AP), known as closed-loop control of blood glucose in diabetes, is a system combining a glucose sensor, a control algorithm, and an insulin infusion device... AP developments can be traced back 50 years to when the possibility for external blood glucose regulation was established by studies in individuals with type 1 diabetes using intravenous glucose measurement and infusion of insulin and glucose... After the pioneering work by Kadish in 1964, expectations for effectively closing the loop were inspired by the nearly simultaneous work of five teams reporting closed-loop control results between 1974 and 1978: Albisser et al., Pfeiffer et al., Mirouze et al., Kraegen et al., and Shichiri et al.... In all early intravenous and intraperitoneal AP systems, the closed-loop control algorithms belonged to a class known as proportional-derivative controllers, which used blood glucose values and blood glucose rate of change in a relatively straightforward calculation of insulin dose... In September 2006, the Juvenile Diabetes Research Foundation International (JDRF) initiated the Artificial Pancreas Project and funded a consortium of centers to carry out closed-loop control research... So far, encouraging results have been reported by several centers... Two notable achievements were the acceptance by the Food and Drug Administration of the University of Virginia–University of Padova type 1 diabetes simulator as a substitute to animal trials in the preclinical testing of closed-loop control strategies, and the design by a team from the University of California Santa Barbara and the Sansum Diabetes Research Institute of a communication platform allowing the automated transfer of data between CGM, control algorithm, and insulin pump... These first devices had limited performance, particularly in the hypoglycemic range... Since then, significant progress has been made toward versatile and reliable CGM; a number of studies have documented its benefits and charted guidelines for its clinical use... Moreover, with subcutaneous insulin delivery the lost physiological role of the liver in modulating peripheral insulin levels results in higher peripheral insulinemia... Whether such a reduced hepatic insulinization impairs the control of hepatic glucose output significantly is still unclear... The control layers work on different time scales... At the bottom, the fastest layer is in charge of safety requirements... Table 1 summarizes the principal components of a closed-loop system, including the CGM, the insulin infusion device, the control algorithm and the associated human factors, and lists the areas that need further development before the ambulatory AP becomes a reality.

Show MeSH