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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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Principal component of the type 1 diabetes simulator: a model of the glucose-insulin system, a model of the sensor, a model of the insulin pump and subcutaneous insulin kinetics, and the controller to be tested.
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Figure 5: Principal component of the type 1 diabetes simulator: a model of the glucose-insulin system, a model of the sensor, a model of the insulin pump and subcutaneous insulin kinetics, and the controller to be tested.

Mentions: Building on the large scale meal model developed in the healthy state (116,117), we have developed a type 1 diabetes simulator that, thanks to its ability to realistically describe intersubject variability, has been accepted by the Food and Drug Administration as a substitute of preclinical animal trials for certain insulin treatments (32). In this simulator, a virtual human is described as a combination of several glucose and insulin subsystems. To permit in silico experiments using CGM, the model includes subcutaneous glucose transport and sensor errors. In summary, the model consists of 13 differential equations and 35 parameters for each subject (116,117). The simulator is equipped with 100 virtual adults, 100 adolescents, and 100 children, spanning the variability of type 1 diabetic population observed in vivo. Key “biometric” characteristics of these virtual subjects are presented by Kovatchev et al. (32). Figure 5 illustrates the overall design of the simulation model.


Artificial pancreas: past, present, future.

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

Principal component of the type 1 diabetes simulator: a model of the glucose-insulin system, a model of the sensor, a model of the insulin pump and subcutaneous insulin kinetics, and the controller to be tested.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

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

Figure 5: Principal component of the type 1 diabetes simulator: a model of the glucose-insulin system, a model of the sensor, a model of the insulin pump and subcutaneous insulin kinetics, and the controller to be tested.
Mentions: Building on the large scale meal model developed in the healthy state (116,117), we have developed a type 1 diabetes simulator that, thanks to its ability to realistically describe intersubject variability, has been accepted by the Food and Drug Administration as a substitute of preclinical animal trials for certain insulin treatments (32). In this simulator, a virtual human is described as a combination of several glucose and insulin subsystems. To permit in silico experiments using CGM, the model includes subcutaneous glucose transport and sensor errors. In summary, the model consists of 13 differential equations and 35 parameters for each subject (116,117). The simulator is equipped with 100 virtual adults, 100 adolescents, and 100 children, spanning the variability of type 1 diabetic population observed in vivo. Key “biometric” characteristics of these virtual subjects are presented by Kovatchev et al. (32). Figure 5 illustrates the overall design of the simulation model.

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
Related in: MedlinePlus