Development of Algorithms for a Hypoglycemic Prevention Alarm: Closed Loop Study

The study is expected to include a maximum of 80 people who have type 1 diabetes and are
between the ages of 12 - 46 years old.

Your involvement in this research study is expected to take approximately 3-9 months
depending on your decision to continue using the Navigator Continuous Glucose Monitor.

Each subject will have one enrollment visit of approximately 2 hours. You will then return
for one or two 14 hour overnight hospital admissions in the Clinical Research Center (CRC).
After the CRC visit(s) you will be given the option to continue using a Navigator CGM at home
for an additional 13 weeks. If you decide to continue use of the Navigator you will be
scheduled for an additional phone consult or visit to Stanford one week after your hospital
admission. In addition, you will be required to return to Stanford for a final 13 week visit.

Inclusion Criteria:

The inclusion criteria for this study includes the following:

1. Clinical diagnosis of type 1 diabetes and using daily insulin therapy for at least one
year.

2. Age 12.0 years to less than 46.0 years old.

3. Subject has used a downloadable insulin pump for at least 3 months

4. Parent/guardian and subject understand the study protocol and agree to comply with it.

5. Subjects >12.0 years old and primary care giver (i.e., parent or guardian) comprehend
written English.

6. Subject has a home computer with email access.

7. For females, subject not intending to become pregnant during the study.

8. No expectation that subject will be moving out of the area of the clinical center
during the study.

9. Informed Consent Form signed by the parent/guardian and Child Assent Form signed by
subjects ages 12 to 17 years.

10. Subjects cannot have had a severe hypoglycemic event, as described as a seizure, loss
of consciousness, severe neurological impairment, or neurological impairment
suggestive of hypoglycemia and requiring an emergency department visit or
hospitalization within 18 months of enrollment.

Exclusion Criteria:

The exclusion criteria for this study is the following:

1. The presence of a significant medical disorder that in the judgment of the
investigator will affect the wearing of the sensors or the completion of any aspect of
the protocol

2. The presence of any of the following diseases:

- Asthma if treated with systemic or inhaled corticosteroids in the last 6 months

- Cystic fibrosis

- Angina (recurrent heart pain)

- Past heart attack or coronary artery (heart vessel) disease

- Past stroke or impairment of blood flow to the brain

- Other major illness that in the judgment of the investigator might interfere with
the completion of the protocol Adequately treated thyroid disease and celiac
disease do not exclude subjects from enrollment

3. Inpatient psychiatric treatment in the past 6 months for either the subject or the
subject's primary care giver (i.e., parent or guardian)

4. Current use of oral/inhaled glucocorticoids or other medications, which in the
judgment of the investigator would be a contraindication to participation in the study