The iLet Introduction Study: A Feasibility Study of the iLet, a Fully Integrated Bihormonal Bionic Pancreas

Inclusion Criteria: iPhone and iLet BP experiments * Age ≥ 18 years and have had clinical type 1 diabetes for at least one year * Diabetes managed using an insulin pump for ≥ 6 months * Prescription medication regimen stable for \> 1 month (except for medications that will not affect the safety of the study and are not expected to affect any outcome of the study, in the judgment of the principal investigator) iLet Infusion Set Sub-Study * Age ≥ 18 years and have had clinical type 1 diabetes for at least one year * Diabetes managed using an insulin pump for ≥ 6 months Exclusion Criteria: iPhone and iLet BP experiments * Unable to provide informed consent (e.g. impaired cognition or judgment) * Unable to safely comply with study procedures and reporting requirements (e.g. impairment of vision or dexterity that prevents safe operation of the bionic pancreas, impaired memory, unable to speak and read English) * Current participation in another diabetes-related clinical trial that, in the judgment of the principal investigator, will compromise the results of this study or the safety of the subject * Pregnancy (positive urine HCG), breast feeding, plan to become pregnant in the immediate future, or sexually active without use of contraception * Current alcohol abuse (intake averaging \> 3 drinks daily in last 30 days), use of marijuana within 1 month of enrollment, or other substance abuse (use within the last 6 months of controlled substances other than marijuana without a prescription) * Unwilling or unable to refrain on the study days from:acetaminophen in any form, use of marijuana, use of drugs that may dull the sensorium, reduce sensitivity to symptoms of hypoglycemia, or hinder decision making during the period of participation in the study (use of beta blockers will be allowed as long as the dose is stable and the subject does not meet the criteria for hypoglycemia unawareness while taking that stable dose, but use of benzodiazepines or narcotics, even if by prescription, may be excluded according to the judgment of the principal investigator) * History of liver disease that is expected to interfere with the anti-hypoglycemia action of glucagon (e.g. liver failure or cirrhosis). Other liver disease (i.e. active hepatitis, steatosis, active biliary disease, any tumor of the liver, hemochromatosis, glycogen storage disease) may exclude the subject if it causes significant compromise to liver function or may do so in an unpredictable fashion. * Renal failure on dialysis * Personal history of cystic fibrosis, pancreatitis, pancreatic tumor, or any other pancreatic disease besides type 1 diabetes * Any known history of coronary artery disease including, but not limited to, history of myocardial infarction, stress test showing ischemia, history of angina, or history of intervention such as coronary artery bypass grafting, percutaneous coronary intervention, or enzymatic lysis of a presumed coronary occlusion) * Congestive heart failure (established history of CHF, lower extremity edema, paroxysmal nocturnal dyspnea, or orthopnea) * History of TIA or stroke * Seizure disorder, history of any non-hypoglycemic seizure within the last two years, or ongoing treatment with anticonvulsants * History of hypoglycemic seizures (grand-mal) or coma in the last year * History of pheochromocytoma: fractionated metanephrines will be tested in patients with history increasing the risk for a catecholamine secreting tumor: Episodic or treatment refractory (requiring 4 or more medications to achieve normotension) hypertension, Paroxysms of tachycardia, pallor, or headache, Personal or family history of MEN 2A, MEN 2B, neurofibromatosis, or von Hippel-Lindau disease * History of adrenal disease or tumor * Hypertension with systolic BP ≥160 mm Hg or diastolic BP ≥100 despite treatment * Untreated or inadequately treated mental illness (indicators would include symptoms such as psychosis, hallucinations, mania, and any psychiatric hospitalization in the last year), or treatment with anti-psychotic medications that are known to affect glucose regulation. * Electrically powered implants (e.g. cochlear implants, neurostimulators) that might be susceptible to RF interference * History of adverse reaction to glucagon (including allergy) besides nausea and vomiting * Established history of allergy or severe reaction to adhesive or tape that must be used in the study * Use of oral (e.g. thiazolidinediones, biguanides, sulfonylureas, glitinides, DPP-4 inhibitors, SGLT-2 inhibitors) anti-diabetic medications * Hemoglobin \< 12 g/dl * Any factors that, in the opinion of the principal investigator would interfere with the safe completion of the study iLet Infusion Set Sub-Study * Unable to provide informed consent (e.g. impaired cognition or judgment) * Unable to safely comply with study procedures and reporting requirements (e.g. impairment of vision or dexterity that prevents safe operation of their insulin pump, impaired memory, unable to speak and read English) * Pregnancy (positive urine HCG), breast feeding, plan to become pregnant in the immediate future, or sexually active without use of contraception * Hemoglobin \< 11 g/dl * Unable to establish IV access, or subject reports difficult IV access in the past * History of allergy or severe reaction to adhesive or tape that must be used in the study