NCT04771403

Two Way Crossover Closed Loop Study MPC vs FMPD

A Randomized, Two-way, Cross-over Study to Assess the Efficacy of an MPC Exercise-enabled Closed-loop System vs FMPD Exercise-enabled Closed-loop System

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 25 (actual)
• Sponsor: Oregon Health and Science University · Academic / Other
• Sex: All
• Age: 21 Years – 50 Years
• Healthy volunteers: Not accepted

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.

Detailed description

Participants will undergo two approximately 76 hour studies. During each of these intervention visits, participants will wear an Omnipod to deliver insulin and a Dexcom G6 CGM to measure glucose. The CGM system will provide sensed glucose data every 5 minutes. Sensed glucose data will be wirelessly transmitted via Bluetooth Low Energy (BTLE) from the Dexcom G6 transmitter to the Samsung master controller every five minutes. The smart phone will wirelessly communicate via BTLE to an Omnipod through an Omnipod PDM. During one of the studies, glucose will be controlled using the MPC AP. During another study, glucose will be controlled using the FMPD AP. The AP system will receive activity data through a Polar M600 watch worn by the participant. Participants will arrive at the clinic at approximately 7am for the inpatient visits. Participants will eat breakfast, lunch and dinner in the clinic. Participants will perform activities of daily living and exercise using an aerobic exercise video. Participants will discharge at 7pm to go home for the remainder of the study visit and perform one exercise video session at home. Participants will return to OHSU on Day 4 for removal of all devices. The exception to this is for the first 8 participants using the MPC AP. These participants will stay at the research clinic during the day and go home to sleep each night (7pm-7am).

Conditions

• Type 1 Diabetes

Interventions

Type	Name	Description
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.

Timeline

• Start date: 2021-02-23
• Primary completion: 2022-03-10
• Completion: 2022-03-10
• First posted: 2021-02-25
• Last updated: 2023-05-17
• Results posted: 2023-05-17

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated device study