This is an open label, interventional, monocentric, prospective early feasibility study, designed to evaluate the safety of implant and short-term integration into the tissue of the YANG sensor. In addition, the set up will enable data collection which will be used to develop the software algorithm to allow real-time, continuous measurement of glucose, ketone and lactate levels in the interstitial fluid in adults with diabetes mellitus, in a future version of the device.

Inclusion Criteria:

T1DM patients

• Subjects willing to sign an informed consent form (ICF),
• Adult subjects, age ≥ 18, ≤ 50 years old
• Body Mass Index (BMI) 20≥, ≤ 27.5 [kg/m2]
• Subjects willing to comply to study protocol requirements (exercises, ketone ester drinks, alcohol, study visits, blood sampling etc)
• Patients with type 1 diabetes mellitus (T1DM) according to WHO criteria, diagnosed for at least 12 months prior to screening
• Subjects being on insulin pump for at least 12 months

Healthy Volunteers

• Subjects willing to sign an informed consent form (ICF),
• Adult subjects, age ≥ 18, ≤ 50 years old
• BMI 20≥, ≤ 27.5
• Subjects willing to comply to study protocol requirements (exercises, ketone ester drinks, alcohol, study visits, blood sampling etc)
• Healthy subjects, as self-declared and confirmed by screening assessments and Principal Investigator's judgment

Exclusion Criteria:

• Subjects with a contraindication to undergo challenging tests (i.e., ischemic heart disease, epilepsy, panhypopituitarism, hypoadrenalism, hypothyroidism, known allergic reaction to ibuprofen/paracetamol/acetylsalicylic acid)
• For people with diabetes: History of severe hypoglycaemia in the previous 6 months. Severe hypoglycaemia is defined as hypoglycaemia resulting in loss of consciousness or seizure
• For people with diabetes: History of diabetic ketoacidosis requiring emergency room visit or hospitalization in the previous 6 months
• Any blood disorder identified by haematocrit <30% or >55%
• History of hepatitis B, hepatitis C, or HIV
• A condition requiring or likely to require magnetic resonance imaging (MRI) during the study duration
• Female subjects who are pregnant, planning on becoming pregnant or nursing
• Any disorder, which in the investigator's opinion might jeopardise subject's safety or compliance with the protocol.
• Coagulation disorder, wound healing and bleeding disorder or taking anticoagulant medication
• Any long-term drug treatments other than insulin, such as statins, low-dose aspirin, fibrates etc.
• The presence of any other active implanted device except for insulin pumps (as defined further in protocol)
• The presence of any other CGM sensor or transmitter located in abdomen (other location is acceptable)
• Impaired fasting glucose or impaired glucose tolerance (for healthy volunteers)
• Any contraindication to the use of the Yang system as listed in the device IFU (i.e. any known allergy to PDMS)