This is a prospective, single arm, open-label, interventional, pilot study to evaluate the accuracy and precision of the continuous glucose monitoring (CGM) system of i-SENS, Inc., CareSens Air 3, in adult patients with type 1 diabetes.

Participants will wear two CareSens Air 3 and one Libre 3 Plus for 16 days without access to glucose values from the CareSens Air 3 devices while maintaining their original diabetes mellitus treatment. The participants will draw capillary blood at least 8 times a day using the SMBG system between study visits.

Between insertion and removal of the CareSens Air 3 the participants will be in the clinic 4 times to obtain accurate glucose reading from the reference device under carefully controlled circumstances including induction of low and high blood glucose.

Inclusion Criteria:

• Adults who are 18-65 years of age, inclusive
• Patients with type 1 diabetes who use intensive insulin therapy (multiple daily injections (MDI) or continuous subcutaneous insulin infusion (CSII) including users of systems with continuous glucose monitoring (CGM) driven automatic adjustment of insulin doses for at least 3 months
• Patients who voluntarily decide to participate in the study and provide written informed consent

Exclusion Criteria:

• The following abnormal skin or skin diseases or skin alterations at the CGM sensor attachment or insertion site: Severe psoriasis, recent burn injury or severe sunburn, severe eczema, severe scar, extensive tattoo, dermatitis herpetiformis, severe rash, Staphylococcus aureus infection.
• Allergic contact dermatitis to medical adhesives.
• History of frequent catheter abscesses associated with pump therapy.
• Severe hypoglycemia events within 3 months prior to screening. Severe hypoglycemia is defined as loss of consciousness or seizure requiring emergency medical treatment due to hypoglycemia.
• Hypoglycemia unawareness.
• Conditions that predispose to hypoglycemia including inadequately treated thyroid and adrenal disease.
• Participants with diabetic ketoacidosis within 3 months prior to screening.
• History of epilepsy or syncope within 6 months prior to screening.
• Unstable vascular diseases (defined by event or increasing symptoms in the last 6 months) or with insufficient therapy, including: Stroke, transitory cerebral ischemia, ischemic heart disease, peripheral vascular disease, and serious arrhythmia.
• Patients with anemia (hemoglobin below normal range).
• Patients scheduled for X-ray, MRI, CT or diathermy during the study.
• Pregnant or lactating women or those who plan to become pregnant or do not agree to use an adequate method of contraception during the study.
• Patients who are currently participating or participated within 2 weeks prior to screening in another study or plan to participate in another study that in the opinion of the investigator would affect the safety of the study participant or the study result.
• Patients unwilling to abstain from ingesting the foodstuffs listed in Appendix 3 in excess of the allowed amounts.
• Patients with cognitive impairment or who are not suitable for this study or may be at increased risk associated with study participation in the opinion of the investigator.
• Wearing of a pace maker or other comparable medical devices.
• HbA1c >9.5%.
• Dependency from the sponsor or the clinical investigator.
• Unwillingness and/or inability to comply with study procedures.

The plan is to publish the results, but to keep the individual data proprietary.

The CareSens Air 3 data will neither be available to the investigational site nor the participants during the course of the study.