Outpatient Pump Shutoff Pilot Feasibility and Efficacy Study

Patients who are eligible for the clinical trial initially will use a Medtronic Continuous
Glucose Monitor (CGM) at home to verify that the subject is able to use the CGM and insert
sensors. Subjects already using a Medtronic CGM will skip this phase, provided that the
eligibility criteria for CGM use and the study are met.

Patients who meet criteria for sensor use and the study will then use the closed-loop system
at home for 5 days to demonstrate their ability to use the system and submit study data to
the Coordinating Center.

Patients who successfully demonstrate their ability to use the system at home as described
above will be eligible for the randomized trial phase. This phase consists of use of the
full system as an outpatient for approximately 42 nights:

- Each night the blood glucose level will be checked with the study home blood glucose
(BG) meter and used to perform a calibration of the CGM. This calibration must occur
no more than 90 minutes prior to activation of the system. NOTE: Patients will be
instructed to calibrate the CGM per manufacturer guidelines.

- Then the system will be activated, linking the CGM and insulin pump to the computer at
the bedside.

- A randomization schedule on the laptop will be used to determine whether the 'pump shut
off' application will be active that night or not.

- Patients will be blinded as to whether the pump shut off is active when a session is
initiated each night.

- There will not be an alarm if the pump shuts off. The CGM alarm will be set to 60
mg/dL (3.3 mmol/L). When a CGM alarm occurs, the patient will be asked to measure the
blood glucose with a BG meter, if he/she is aware of the alarm.

- The time period for outcome assessment each night will be from the time the system is
activated until it is turned off in the morning

- Pump shut off, when it occurs, will be for up to 2 hours. Multiple instances of pump
suspension can occur if there are recurrent predictions of hypoglycemia during the
night.

- Patients will be asked to check blood glucose with the study BG meter, blood ketones
with the study ketone meter, and urine ketones with a ketone strip each morning prior
to breakfast and enter the results on the study laptop. The patient will be instructed
to contact the study physician if the blood glucose or ketone readings are out of an
expected range. Patients will be contacted if these morning safety values are not
reported as required or are out of range.

- Patients will be asked to record all overnight carbohydrate intake on the study laptop.

- Patients will be asked to perform periodic data uploads using the study laptop.
Monitoring processes will ensure that the patient is contacted if these uploads do not
occur as required, or if review of an upload reveals any extreme, prolonged episodes of
low or high blood glucose readings, or elevated morning blood glucose, blood ketone, or
urine ketone values.

Upon completion of the study, patients as well as study clinicians will be asked to complete
a questionnaire regarding use of the study system.

There will be one follow-up visit after 21 days in the clinical trial and a second follow-up
visit after the completion of 42 nights of successful study system use. A successful night
of study system use is defined as use of the system for at least four hours. Phone contacts
with the patients will be made once a week.

Inclusion Criteria:

- Clinical diagnosis of type 1 diabetes and using daily insulin therapy for at least
one year and an insulin infusion pump for at least 6 months

- Age >/= 15.0 - 45 years

- HbA1c
- Availability of internet access for periodic upload of study data

Exclusion Criteria:

- Diabetic ketoacidosis in the past 3 months

- Hypoglycemic seizure or loss of consciousness in the past 6 months

- History of seizure disorder (except for hypoglycemic seizure)

- History of any heart disease including coronary artery disease, heart failure, or
arrhythmiasCoronary artery disease or heart failure

- Cystic fibrosis

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

- History of ongoing renal disease (other than microalbuminuria), or liver disease
(Creatinine > 1.5 mg/dL (0.08 mmol/L))

- Medical or psychiatric condition that in the judgment of the investigator might
interfere with the completion of the protocol such as:

- Inpatient psychiatric treatment in the past 6 months

- Uncontrolled adrenal disorder

- Abuse of alcohol

- Pregnancy

- Liver disease as defined by an ALT greater than 3 times the upper limit of normal