Evaluation of a Percutaneous Optical Fibre Glucose Sensor (FiberSense System)

Inclusion Criteria: * Male or female age ≥ 18 years old. * Nondiabetic subjects with normal fasting plasma glucose and HbA1c (≤5.6%) * Women who are not pregnant, lactating or planning a pregnancy during their participation in the clinical study. * Willingness, ability and commitment to comply with the testing, procedure and follow-up outlined in this protocol including (but not limited to) frequency of clinic visits and use of pre-specified glucose monitoring devices. * Willingness to abstain from bathing and swimming during their participation in the measurement phase. * In the opinion of the investigator, absence of any physical limitations, addictive diseases, or underlying medical conditions (including mental health) that may preclude the patient from being a good study candidate. * Written informed consent to participate in the study provided by the patient. Exclusion Criteria: * Currently pregnant, as demonstrated by a positive pregnancy test at screening and on day of first sensor insertion * Impaired hepatic function measured as alanine aminotransferase (ALT) or aspartate aminotransferase (AST) ≥ three times the upper reference limit. * Impaired renal function measured as serum creatinine \> 1.2 times above the upper limit of normal. * Any active acute or chronic disease or condition that, in the opinion of the investigator, might interfere with the performance of this study. * Any active acute or chronic infectious disease that, in the opinion of the investigator, would pose an excessive risk to study staff. * Current use or recent exposure to any medication that in the opinion of the investigator could have an influence on the patient's ability to participate in this study or on the performance of the test device. * Extensive skin changes/diseases that preclude wearing the required number of devices on normal skin at the proposed application sites (e.g., extensive psoriasis, recent burns or severe sunburn, extensive eczema, extensive scarring, extensive tattoos, dermatitis herpetiformis). * Have a known allergy to medical-grade adhesives, or known hypersensitivity to any of the products used in the study. * Known current or recent alcohol or drug abuse * Blood donation of more than 500 ml within the last three months * Currently participating in another investigational study protocol where the testing or results may interfere with study compliance, diagnostic results, or data collection. * History of epilepsy * History of cardiac arrhythmias * Clinically significant abnormality on ECG at screening * An identified protected vulnerable patient (including but not limited to those in detention, or a prisoner).