Multivariable Recursive Subspace Identification with Application to Artificial Pancreas Systems
Autor: | Sediqeh Samadi, Jianyuan Feng, Kamuran Turksoy, Caterina Lazaro, Mudassir Rashid, Elizabeth Littlejohn, Nicole Frantz, Iman Hajizadeh, Mert Sevil, Ali Cinar, Zacharie Maloney |
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Rok vydání: | 2017 |
Předmět: |
0209 industrial biotechnology
Engineering State-space representation Mean squared error business.industry Multivariable calculus System identification 030209 endocrinology & metabolism Pattern recognition 02 engineering and technology Variance (accounting) Artificial pancreas 03 medical and health sciences Identification (information) 020901 industrial engineering & automation 0302 clinical medicine Control and Systems Engineering Control theory Artificial intelligence business Subspace topology |
Zdroj: | IFAC-PapersOnLine. 50:886-891 |
ISSN: | 2405-8963 |
Popis: | Designing a fully automated artificial pancreas (AP) system is challenging. Changes in the glucose-insulin dynamics in the human body over time, and the inter-subject and day-to-day variability of people with type 1 diabetes (T1D) are two important factors that would highly undermine the performance of an AP that is based on time-invariant and non-individualized models. People with T1D show different responses to carbohydrate intake, insulin, physical activity and stress with day-to-day variability present between or within specific patients. Thus, the control law in an AP system requires a reliable time-varying individualized model to perform efficiently. In this work, a novel recursive identification approach called a Predictor-Based Subspace Identification (PBSID) method is used for identifying a linear time-varying glucose-insulin model for each individual. Model identification and validation are based on clinical data from closed-loop experiments. The models are evaluated by means of various performances indices: Variance Accounted For (VAF), Root mean square error (RMSE), Normalized root mean square error (NRMSE) and Normalized mean square error (NMSE). The proposed method provides a stable time-varying state space model over time. It can be also individualized for each patient by defining the order of the system correctly. The approach proposed in this work has shown a strong potential to identify a consistent glucose-insulin model in real time for use in an AP system. |
Databáze: | OpenAIRE |
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