This study evaluates the usability of the KOS Argus Continuous Glucose Monitoring (CGM) System, a noninvasive, wrist-worn device that estimates blood glucose levels using light-based sensors and artificial intelligence algorithms. The Argus device does not puncture the skin or require sensor insertions.

The study will enroll up to 100 adults with type 1 diabetes, type 2 diabetes, or prediabetes at a single site. Participants will complete a screening visit, followed by a Day 1 in-clinic baseline visit that includes serial venous blood draws approximately every 10 minutes over 6 hours to collect paired reference blood glucose measurements alongside Argus device readings. After the baseline visit, participants will wear the Argus device and a commercially available Dexcom Stelo CGM continuously for 15 days during normal daily activities.

The primary objective is to collect paired glucose data to support device development and algorithm training. Participants will not receive glucose readings from the Argus device and will continue their usual diabetes management throughout the study. Secondary objectives include assessing device safety, tolerability, adherence, and operational lifespan over the 15-day wear period.

The KOS Argus CGM System is a noninvasive, wrist-worn device that uses multi-spectral photoplethysmography (PPG) sensors combined with AI-driven algorithms to estimate blood glucose levels. The device measures volumetric, optical, and vascular tone variations in peripheral blood flow using three different wavelengths of light to create a comprehensive picture of tissue dynamics.

This is a prospective, open-label, single-center study. Participants will complete three visits: a screening visit (Day -8 to Day -7), an in-clinic baseline visit (Day 1), and a final visit (Day 15).

At the screening visit, informed consent will be obtained, eligibility will be assessed, and screening procedures will be performed, including vital signs, electrocardiogram, and laboratory testing. Eligible participants will return for the Day 1 baseline visit, during which both the Argus device and a Dexcom Stelo CGM will be placed. Serial venous blood samples will be collected via intravenous line approximately every 10 minutes over a 6 hour period and analyzed at the site laboratory. Each participant is expected to contribute approximately 37 paired reference blood glucose measurements during this visit, yielding approximately 3,700 total paired measurements across the study population.

Following the baseline visit, participants will wear both the Argus CGM and the Dexcom Stelo CGM continuously for 15 days during normal daily activities. Participants will perform a reference glucose measurement using a Contour Next One fingerstick glucose meter every 5 days and will log meals, medications, and activities in the Argus mobile application. Paired Argus and Dexcom Stelo CGM data are expected to yield approximately 350,000 to 432,000 matched data points across the study population based on a 5 minute sampling interval.

The Argus device has been determined to be a non-significant risk device. Participants will be blinded to Argus glucose output and will not use Argus readings for any treatment decisions. All glucose management will continue according to each participant's usual standard of care.

Primary endpoints include the quantity and quality of paired Argus and reference laboratory blood glucose measurement data collected during the Day 1 in-clinic visit, and paired Argus and Dexcom Stelo CGM data collected during the 15 day home-wear period. Secondary endpoints include device adherence measured as the number of hours of active device time, device lifespan measured as the number of hours before device failure, and user input via survey. Safety endpoints include adverse events, serious adverse events, and device-related events. No formal hypothesis testing is planned.

Inclusion Criteria:

• Provision of signed and dated informed consent form
• Male or female, aged 18 years and older
• Clinical diagnosis of type 1 or type 2 diabetes and/or prediabetes for any duration
• Sufficient venous access for one IV line
• Stated willingness to comply with all study procedures and availability for the duration of the study
• Willing to wear the required number of CGM systems for the total duration of the study (up to 15 days of total wear), including up to two Argus devices and at least one provided, commercially available, CGM device
• Willing and able to use a compatible personal iOS or Android smartphone with - Bluetooth capability to install and use the study application, and to pair and maintain continuous Bluetooth communication between the smartphone and the investigational device for the required wear period
• Has reliable access to their personal smartphone for the duration of participation and agrees to keep Bluetooth enabled and the study app running as instructed

Exclusion Criteria:

• Known or suspected hypersensitivity to any of the components of the investigational device
• Known allergy to medical grade adhesives
• Presence of any injury, infection, atypical skin condition (such as hyperkeratosis or hyperpigmentation) or tattoo on the wrists
• Participation in any clinical trial investigation of a medical device or any medicinal product in clinical development within 30 days
• Required or scheduled to have a Magnetic Resonance Imaging (MRI) scan, Computed Tomography (CT) scan, or diathermy during the study wear period
• Blood donation or blood loss of more than 500 mL within the last 3 months
• Presence of anemia as demonstrated by hematocrit measurements below 36.0% for males or 33.0% for females
• Presence of an active implantable medical device such as a pacemaker
• Presence or history of a cardiovascular disease including stable and unstable angina pectoris, myocardial infarction, transient ischemic attack, stroke, cardiac decompensation, clinically significant arrhythmias, or clinically significant conduction disorders
• Any history or presence of cancer except basal cell skin cancer or squamous cell skin cancer
• Presence of signs of acute illness or immunodeficiency Presence of any serious systemic infectious disease during four weeks prior to the intervention
• Presence of clinically significant abnormal screening laboratory tests or standard 12 lead electrocardiogram after 5 minutes resting in supine position at screening
• History of significant alcohol or drug abuse, or current alcohol consumption exceeding approximately two standard drinks per day for males or one standard drink per day for females
• Inability or unwillingness to refrain from smoking for the duration of visits History of diagnosis for hepatitis B, hepatitis C, HIV 1, or HIV 2
• Clinically relevant comorbidity capable of constituting a risk for the participant or interfering with interpretation of data as judged by the investigator, including but not limited to end stage renal disease currently managed by dialysis or anticipating initiating dialysis during the study wear period, current usage of hydroxyurea medications, or significant usage of acetaminophen over 1 g every 6 hours
• Mental incapacity, unwillingness, or language barriers precluding adequate understanding or cooperation Pregnancy or current breastfeeding
• Current or past affiliation with the investigational site, sponsor, or study personnel, including being an employee, contractor, or immediate family member of any individual directly involved in the trial, or current employment with, contractor relationship with, or significant financial interest in companies involved in glucose monitoring or diabetes related products that could create a conflict of interest or bias study results
• Consideration of unsuitability for inclusion by investigator Inability or unwillingness to use a compatible personal smartphone to install and operate the study app and maintain Bluetooth connectivity as required

Participants are blinded to Argus CGM glucose output throughout the study. Glucose readings from the Argus device are not displayed to participants or used for treatment decisions. However, participants and study staff are aware of device placement and study procedures.