Human-in-the-Loop Insulin Dosing

The last ten years of efforts in developing automated insulin dosing systems have led to one hybrid closed-loop device in the US market with more in the late stages of development. Much of the focus has been on algorithms, including closed-loop, detection of sensor and pump faults, and safety. There has been less discussion in the open literature about user interface design and related options. This article provides perspectives on automated insulin delivery (AID) system design by analyzing commonly used devices, such as bicycles and car entertainment systems. The recent Boeing 737 Max 8 disasters are used to highlight related challenges with AID systems. The role that system engineers can play in the do it yourself artificial pancreas system movement is also discussed. The human-in-the-loop remains by far the most important “component” of any AID system.

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Survey about do-it-yourself closed loop systems in the treatment of diabetes in Germany

PLoS ONE ◽

10.1371/journal.pone.0243465 ◽

2020 ◽

Vol 15 (12) ◽

pp. e0243465

Author(s):

Anna Laura Herzog ◽

Jonas Busch ◽

Christoph Wanner ◽

Holger K. von Jouanne-Diedrich

Keyword(s):

Blood Glucose ◽

Glucose Control ◽

Closed Loop ◽

Artificial Pancreas ◽

Direct Interaction ◽

Loop System ◽

Closed Loop System ◽

Glucose Levels ◽

Blood Glucose Levels ◽

Do It Yourself

Continuous glucose monitoring (CGM) improves treatment with lower blood glucose levels and less patient effort. In combination with continuous insulin application, glycemic control improves and hypoglycemic episodes should decrease. Direct feedback of CGM to continuous subcutaneous insulin application, using an algorithm is called a closed-loop (CL) artificial pancreas system. Commercial devices stop insulin application by predicting hypoglycemic blood glucose levels through direct interaction between the sensor and pump. The prediction is usually made for about 30 minutes and insulin delivery is restarted at the previous level if a rise in blood glucose is predicted within the next 30 minutes (hybrid closed loop system, HCL this is known as a predictive low glucose suspend system (PLGS)). In a fully CL system, sensor and pump communicate permanently with each other. Hybrid closed-loop (HCL) systems, which require the user to estimate the meal size and provide a meal insulin basis, are commercially available in Germany at the moment. These systems result in fewer hyperglycemic and hypoglycemic episodes with improved glucose control. Open source initiatives have provided support by building do-it-yourself CL (DIYCL) devices for automated insulin application since 2014, and are used by a tech-savvy subgroup of patients. The first commercial hybrid CL system has been available in Germany since September 2019. We surveyed 1054 patients to determine which devices are currently used, which features would be in demand by potential users, and the benefits of DIYCL systems. 9.7% of these used a DIYCL system, while 50% would most likely trust these systems but more than 85% of the patients would use a commercial closed loop system, if available. The DIYCL users had a better glucose control regarding their time in range (TIR) and glycated hemoglobin (HbA1c).

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Using a Do-It-Yourself Artificial Pancreas: Perspectives from Patients and Diabetes Providers

Journal of Diabetes Science and Technology ◽

10.1177/1932296820942258 ◽

2020 ◽

Vol 14 (5) ◽

pp. 860-867 ◽

Cited By ~ 1

Author(s):

Walter Palmer ◽

Siri Atma W. Greeley ◽

Lisa R. Letourneau-Freiberg ◽

Rochelle N. Naylor

Keyword(s):

Glycemic Control ◽

Artificial Pancreas ◽

Patient Survey ◽

Endocrine Society ◽

The Us ◽

Time In Range ◽

Do It Yourself ◽

Provider Survey ◽

Diabetes Educators ◽

E Mail

Background: A growing number of people with diabetes are choosing to adopt do-it-yourself artificial pancreas system (DIYAPS) despite a lack of approval from the US Food and Drug Administration. We describe patients’ experiences using DIYAPS, and patient and diabetes providers’ perspectives on the use of such technology. Methods: We distributed surveys to patients and diabetes providers to assess each group’s perspectives on the use of DIYAPS. The patient survey also assessed glycemic control and impact on sleep. The patient survey was distributed in February 2019 via Facebook and Twitter ( n = 101). The provider survey was distributed via the American Association of Diabetes Educators’ e-mail newsletter in April 2019 and the Pediatric Endocrine Society membership e-mail list in May 2019 ( n = 152). Results: Patients overwhelmingly described improvements in glycemic control and sleep quality: 94% reported improvement in time in range, and 64% reported improvement in all five areas assessed. Eighty-nine percent of patients described DIYAPS as “Safe” or “Very Safe,” compared to only 27% of providers. Most felt encouraged by their diabetes provider to continue using DIYAPS, but few described providers as knowledgeable regarding its use. Providers cited a lack of experience with such systems and an inability to troubleshoot them as their most significant challenges. Conclusions: Despite evidence that DIYAPS usage is increasing, our surveys suggest that patients’ adoption of this technology and trust in it is outpacing that of diabetes providers. Providers must be aware of this growing population of patients and familiarize themselves with DIYAPS to support patients using this technology.

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Expectations and Attitudes of Individuals With Type 1 Diabetes After Using a Hybrid Closed Loop System

The Diabetes Educator ◽

10.1177/0145721717697244 ◽

2017 ◽

Vol 43 (2) ◽

pp. 223-232 ◽

Cited By ~ 36

Author(s):

Esti Iturralde ◽

Molly L. Tanenbaum ◽

Sarah J. Hanes ◽

Sakinah C. Suttiratana ◽

Jodie M. Ambrosino ◽

...

Keyword(s):

Quality Of Life ◽

Type 1 Diabetes ◽

Closed Loop ◽

Artificial Pancreas ◽

Perceived Benefits ◽

The Us ◽

System Use

Purpose The first hybrid closed loop (HCL) system, which automates insulin delivery but requires user inputs, was approved for treatment of type 1 diabetes (T1D) by the US Food and Drug Administration in September 2016. The purpose of this study was to explore the benefits, expectations, and attitudes of individuals with T1D following a clinical trial of an HCL system. Methods Thirty-two individuals with T1D (17 adults, 15 adolescents) participated in focus groups after 4 to 5 days of system use. Content analysis generated themes regarding perceived benefits, hassles, and limitations. Results Some participants felt misled by terms such as “closed loop” and “artificial pancreas,” which seemed to imply a more “hands-off” experience. Perceived benefits were improved glycemic control, anticipated reduction of long-term complications, better quality of life, and reduced mental burden of diabetes. Hassles and limitations included unexpected tasks for the user, difficulties wearing the system, concerns about controlling highs, and being reminded of diabetes. Conclusion Users are willing to accept some hassles and limitations if they also perceive health and quality-of-life benefits beyond current self-management. It is important for clinicians to provide a balanced view of positives and negatives to help manage expectations.

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Efficient Closed Loop Simulation of Do-It-Yourself Artificial Pancreas Systems

Journal of Diabetes Science and Technology ◽

10.1177/19322968211032249 ◽

2021 ◽

pp. 193229682110322

Author(s):

Jana Schmitzer ◽

Carolin Strobel ◽

Ronald Blechschmidt ◽

Adrian Tappe ◽

Heiko Peuscher

Keyword(s):

Real Time ◽

In Silico ◽

Closed Loop ◽

Artificial Pancreas ◽

Virtual Patients ◽

Simulation Speed ◽

Virtual Population ◽

Speed Up ◽

Do It Yourself

Background: Numerical simulations, also referred to as in silico trials, are nowadays the first step toward approval of new artificial pancreas (AP) systems. One suitable tool to run such simulations is the UVA/Padova Type 1 Diabetes Metabolic Simulator (T1DMS). It was used by Toffanin et al. to provide data about safety and efficacy of AndroidAPS, one of the most wide-spread do-it-yourself AP systems. However, the setup suffered from slow simulation speed. The objective of this work is to speed up simulation by implementing the algorithm directly in MATLAB®/Simulink®. Method: Firstly, AndroidAPS is re-implemented in MATLAB® and verified. Then, the function is incorporated into T1DMS. To evaluate the new setup, a scenario covering 2 days in real time is run for 30 virtual patients. The results are compared to those presented in the literature. Results: Unit tests and integration tests proved the equivalence of the new implementation and the original AndroidAPS code. Simulation of the scenario required approximately 15 minutes, corresponding to a speed-up factor of roughly 1000 with respect to real time. The results closely resemble those presented by Toffanin et al. Discrepancies were to be expected because a different virtual population was considered. Also, some parameters could not be extracted from and harmonized with the original setup. Conclusions: The new implementation facilitates extensive in silico trials of AndroidAPS due to the significant reduction of runtime. This provides a cheap and fast means to test new versions of the algorithm before they are shared with the community.

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Open Source Closed-Loop Insulin Delivery Systems: A Clash of Cultures or Merging of Diverse Approaches?

Journal of Diabetes Science and Technology ◽

10.1177/1932296818792577 ◽

2018 ◽

Vol 12 (6) ◽

pp. 1223-1226 ◽

Cited By ~ 20

Author(s):

Katharine D. Barnard ◽

Ralph Ziegler ◽

David C. Klonoff ◽

Katarina Braune ◽

Bettina Petersen ◽

...

Keyword(s):

Closed Loop ◽

Therapeutic Option ◽

Artificial Pancreas ◽

Psychosocial Care ◽

Insulin Delivery ◽

Delivery Systems ◽

Target Range ◽

Related Quality ◽

Do It Yourself ◽

Glycemic Target

Biomedical outcomes for people with diabetes remain suboptimal for many. Psychosocial care in diabetes does not fare any better. “Artificial pancreas” (also known as “closed-loop” and “automated insulin delivery”) systems present a promising therapeutic option for people with diabetes (PWD)—simultaneously improving glycemic outcomes, reducing the burden of self-management, and improving health-related quality of life. In recent years there has emerged a growing movement of PWD innovators rallying behind the mantra #WeAreNotWaiting, developing “do-it-yourself artificial pancreas systems (DIY APS).” Self-reported results by DIY APS users show improved metabolic outcomes such as impressive stability of glucose profiles, significant reduction of A1c, and more time within their glycemic target range. However, the benefits remain unclear for the broader population of PWD beyond these highly engaged, highly tech-savvy users willing and able to engage in the demands of building and maintaining their DIY APS. We discuss the challenges faced by key stakeholder groups in terms of potential collaboration and open debate of these challenges.

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