Single Hormone Closed Loop Study With PDT Sensor
Condition: Type 1 Diabetes Mellitus
MeSH terms: Diabetes Mellitus, Type 1
Study type: Interventional

Summary: 
      The study described within this protocol is designed to test a single hormone closed-loop
      algorithm for managing blood glucose in type 1 diabetes using insulin only and a new device
      for measuring glucose continuously in the immediate vicinity of subcutaneous insulin
      delivery. Subjects will undergo one all day closed loop study using insulin only. The closed
      loop insulin only system includes a Dexcom G5 transmitter, a Nexus 5 smart phone and two
      Tandem tslim pumps connected to two Pacific Diabetes Technologies glucose sensing cannulas.
      The closed loop system will be started after G5 2 hour sensor start-up with an IV catheter
      for frequent blood withdrawal for 10 hours.
    

Detailed description: 
      Subjects will undergo one 12 hour inpatient study. During this intervention visit, subjects
      will wear the single hormone closed loop system which includes two t:slim insulin pumps to
      deliver insulin or saline through two investigational PDT glucose sensing cannulas, and a
      Dexcom G5 CGM to measure glucose. The subject will come to the research center at
      approximately 7am for the inpatient visit. The Dexcom G5 sensor and PDT glucose sensing
      cannulas will be placed after arrival. An 18-22 gauge IV catheter will be placed for blood
      sampling every 15 minutes after sensor warm-up is complete for measuring blood glucose
      concentration. After a 2 hour warm-up period for the G5 sensor, glucose will be controlled
      using the FMPD single hormone mode. The single hormone mode of the controller determines
      insulin delivery rates based on proportional and derivative error through one t:slim insulin
      pump. The second t:slim insulin pump will deliver normal saline at the same delivery rates as
      the insulin. Subjects will eat breakfast and lunch at approximately 11 am and 3 pm
      respectively. Subjects will have the ability to complete light exercise on a treadmill. The
      closed loop system will be stopped at approximately 6pm with removal of all devices.

      During the study, the subject will wear one subcutaneous DexcomTM G5 continuous glucose
      monitoring (CGM) system. The CGM system will provide sensed glucose data every 5 minutes. The
      accuracy of the sensed data will be obtained by reference measurements of two YSI venous
      blood glucose values to calibrate the sensor at the beginning of the closed loop study.
      Sensed glucose data will be wirelessly transmitted via Bluetooth Low Energy (BTLE) from the
      Dexcom G5 transmitter to the Nexus 5 master controller every five minutes. The controller is
      a Google Nexus 5 phone. The smart phone will wirelessly communicate via BTLE to two Tandem
      t:slim insulin pumps, one for automated insulin delivery and one of automated saline
      delivery.
    

Intervention name(s): Artificial Pancreas Control system (APC); Pacific Diabetes Technologies CGM Insulin Infusion system
Intervention type(s): Device; Device
Intervention description(s): This intervention is a single hormone closed loop system including a Nexus 5 smart phone, two tslim insulin pumps, a Dexcom G5 CGM and two PDT glucose sensing cannulas that together make up a new experimental, investigational device system. The algorithm included in the APC is an automated version of the Fading Memory Proportional Derivative (FMPD) insulin and glucagon control algorithm.; An integrated combination CGM/insulin infusion system
Intervention MeSH terms: Pancrelipase
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Device Feasibility