The International Diabetes Closed Loop (iDCL) Trial: Protocol 4

Inclusion Criteria:

   - Clinical diagnosis, based on investigator assessment, of type 1 diabetes for at least
   one year and using insulin for at least 1 year

   - Using an insulin pump for at least 3 months (which may include use of automated
   features)

   - Familiarity and use of a carbohydrate ratio for meal boluses

   - Age ≥18.0 years old

   - For females, not currently known to be pregnant. If female and sexually active, must
   agree to use a form of contraception to prevent pregnancy while a participant in the
   study. A negative serum or urine pregnancy test will be required for all females of
   child-bearing potential. Participants who become pregnant will be discontinued from
   the study. Also, participants who during the study develop and express the intention
   to become pregnant within the timespan of the study will be discontinued.

   - If using a personal CGM, willingness to use a Dexcom G6 CGM and discontinue personal
   CGM use during the study

   - Willing not to begin use of, or not to continue use of if currently using, a personal
   AID (closed loop control) system during the study; note if the system offers an
   open-loop mode or can be switched to a PLGS mode that is compatible with the Dexcom
   G6, the system may be used during the study in these modes only

   - Willingness to switch to lispro (Humalog) or aspart (Novolog) if not using already,
   and to use no other insulin besides lispro (Humalog) or aspart (Novolog) during the
   study

   - Willingness not to start any new non-insulin glucose-lowering agent during the course
   of the trial, and not to use Afrezza during the trial

   - Investigator believes that the participant can successfully and safely operate all
   study devices and is capable of adhering to the protocol

Exclusion Criteria:

   - Use of Afrezza or any non-insulin glucose-lowering agent other than metformin
   (including GLP-1 agonists, DPP-4 inhibitors, SGLT-2 inhibitors, sulfonylureas) unless
   participant is willing to discontinue during the trial.

   - Two or more episodes of DKA requiring an emergency room visit or hospitalization in
   the past 6 months

   - Two or more episodes of severe hypoglycemia with seizure or loss of consciousness in
   the last 6 months

   - Hemophilia or any other bleeding disorder

   - A medical or other condition that in the opinion of the investigator could create a
   safety concern for the participant or put the study at risk. History of frequent
   severe hypoglycemia or history of frequent severe hyperglycemia and/or ketosis,
   without emergency room visit or hospitalization, due to poor diabetes self-management
   may be disqualifying per investigator judgment

   - Participation in another pharmaceutical or device trial at the time of enrollment or
   during the study