Two Way Crossover Closed Loop Study MPC vs FMPD

Summary

An artificial pancreas (AP) is a control system for automatic insulin delivery. Our group has implemented a fading memory proportional derivative controller (FMPD) for use within an AP control system which has been evaluated in clinical studies. However, the long action of insulin (90 minutes for peak action) makes it challenging to control insulin with a classical proportional derivative system. The study described within this protocol is designed to test the effectiveness of a new model-predictive control (MPC) AP that modulates insulin delivery based on estimated activity level. The potential benefit of this type of AP is that it handles exercise not as a discrete event, but it automatically adjusts insulin delivery based on estimated activity level calculated at every 5 minute cycle. This type of algorithm may significantly improve glucose control over our FMPD AP, which is designed only to detect exercise when activity level goes above a threshold for a specific duration of 45 minutes.

Conditions

• Type 1 Diabetes

Interventions

DEVICE

FMPD AP algorithm

The Fading Memory Proportional Derivative (FMPD) insulin infusion algorithm determines insulin delivery rates based on proportional error, defined as the difference between the current CGM level and the target CGM level, and the derivative error, defined as the rate of change of the CGM. The FMPD algorithm utilizes derivative and proportional glucose errors to determine delivery rates of insulin.

DEVICE

MPC AP system

The Model Predictive Control (MPC) insulin infusion algorithm contains a model within the controller that takes as an input the aerobic metabolic expenditure in addition to the CGM and meal inputs. The algorithm uses heart rate and accelerometer data collected on the patient's body to calculate metabolic expenditure. The metabolic expenditure then acts on the model for the insulin dynamics, whereby more energy expenditure and longer duration exercise can lead to a more substantial effect of insulin on the CGM.

DEVICE

Dexcom G6 Continuous Glucose Monitoring (CGM) System

The Dexcom G6 CGM measures interstitial glucose through a sensor transmitter. This glucose value is reported to the MPC algorithm during this intervention.

Sponsors & Collaborators

• Juvenile Diabetes Research Foundation

  collaborator OTHER

• The Leona M. and Harry B. Helmsley Charitable Trust

  collaborator OTHER

• Oregon Health and Science University

  lead OTHER

Principal Investigators

• Peter Jacobs, PhD · Oregon Health and Science University

• Jessica Castle, MD · Oregon Health and Science University

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

CROSSOVER

Eligibility

Min Age

21 Years

Max Age

50 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2021-02-23

Primary Completion

2022-03-10

Completion

2022-03-10

FDA Device

Yes

Countries

• United States

Study Locations