(74 days)
The Stelo Glucose Biosensor System is an over-the-counter (OTC) integrated Continuous Glucose Monitor (CCGM) intended to continuously measure, record, analyze, and display glucose values in people 18 years and older not on insulin. The Stelo Glucose Biosensor System helps to detect normal (euglycemic) and low or high (dysglycemic) glucose levels. The Stelo Glucose Biosensor System may also the user better understand how lifestyle and behavior modification, including diet and exercise, impact glucose excursion.
The user is not intended to take medical action based on the device output without consultation with a qualified healtheare professional.
The Stelo Glucose Biosensor system (Stelo System) is an over-the-counter (OTC) interoperable continuous glucose monitoring (iCGM) system.
The Stelo Glucose Biosensor system (Stelo System) is an interoperable connected device that measures and displays estimated glucose values for people who are not on insulin. The Stelo System consists of the following components: the Glucose Sensing Subsystem (GSS) and the Mobile Application Subsystem (MAS). The GSS is comprised of the sensor applicator and on-body wearable, which includes a Bluetooth Low Energy (BLE) molded transmitter, adhesive patch and sensor. The sensor is a small and flexible wire, which is inserted by the applicator into subcutaneous tissue where it converts glucose into electrical current. The transmitter's onboard algorithm converts these measurements into estimated glucose values and calculates the glucose rate of change which are sent every 5 minutes to the MAS is an app that can be downloaded to a compatible smart device and that presents glucose readings and qlucose trend to the user every 15 minutes. As such, the most recent displayed glucose value might be up to 15 minutes old. Each sensor session lasts up to 15 days with an extended 12-hour grace period. The grace period allows additional time for the user to change the sensor at a convenient time.
The proposed Stelo System is based on the same mode of operation and mechanism of reaction as the predicate G7 CGM System (K231081), which uses a wire type sensing mechanism that continuously measures interstitial fluid qlucose levels and a BLE enabled radio transmitter to wirelessly communicate CGM data to compatible display devices at regular 5-minute intervals. These data are also able to be reliably and securely transmitted to other digitally connected devices, excluding insulin pens and Automated Insulin Dosing (AID) systems.
The Stelo System uses the same hardware design as the predicate G7 CGM System. The Stelo GSS firmware is designed to support a factory-calibrated only device (without calibration inputs), to extend the sensor wear duration from 10 to 15 days while maintaining the accuracy of the device, and to connect to authorized display devices only (i.e., Stelo MAS). The Stelo MAS includes a redesigned user interface (UI) tailored to the Stelo System's user population to simplify the use of the device. The UI includes an app onboarding specific to the Stelo MAS design and its intended use, the most recent glucose value and trend graph which are updated every 15 minutes, a narrowed glucose range display from 70 mg/dL, and an "Insights" feature providing the time in range percentage with suggestions to help users improve their time in range. The Ul does not provide any glucose or system alerts.
The Dexcom Stelo Glucose Biosensor System is a continuous glucose monitoring (CGM) device intended for over-the-counter (OTC) use by adults aged 18 and older who are not on insulin. The device continuously measures, records, and displays glucose values, helping to detect normal, low, or high glucose levels and allowing users to understand the impact of lifestyle modifications on glucose excursion.
Here's a breakdown of the acceptance criteria and study information:
1. Table of Acceptance Criteria and Reported Device Performance:
The document explicitly states that the device meets the iCGM special controls for clinical performance set forth in 21 CFR 862.1355. While specific numerical acceptance criteria (e.g., MARD values, percentages of readings within certain zones) are not provided in the summary, the general umbrella acceptance criterion is:
| Acceptance Criterion | Reported Device Performance |
|---|---|
| iCGM special controls for clinical performance (21 CFR 862.1355) | Met |
| Device-related adverse event (AE) incidence | Acceptable. Reported AEs included local irritation (edema) and pain/discomfort. |
| Nonclinical performance (e.g., electrical, mechanical, environmental, human factors, software, cybersecurity) | Met pre-defined acceptance criteria |
2. Sample Size Used for the Test Set and Data Provenance:
The document states: "A clinical study was conducted to evaluate the safety and effectiveness of the Stelo Glucose Biosensor System. The effectiveness of the device was evaluated with respect to reference venous plasma sample YSI measurements across the measuring range throughout a 15-day wear duration with a 12-hour grace period in adult (18 years and older) participants with diabetes."
- Test Set Sample Size: The exact number of participants is not specified, but it refers to "adult (18 years and older) participants with diabetes."
- Data Provenance: Prospective clinical study data. The country of origin is not explicitly stated in the provided text.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:
The ground truth for the clinical study was established using "reference venous plasma sample YSI measurements." This usually refers to laboratory-based glucose analysis performed by trained technicians, not "experts" in the context of interpretation (like radiologists). The number and qualifications of technicians are not mentioned.
4. Adjudication Method for the Test Set:
Not applicable, as the ground truth was established through laboratory reference measurements (YSI) of venous plasma samples, which are generally considered the gold standard and do not typically require adjudication.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done:
No, an MRMC comparative effectiveness study was not done. The study evaluated the standalone performance of the Stelo Glucose Biosensor System against reference measurements. The document does not mention any human readers or human-AI interaction in the context of this study.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done:
Yes, a standalone study was done. The clinical study evaluated the Stelo Glucose Biosensor System's effectiveness by comparing its glucose measurements to reference venous plasma YSI measurements, implying an assessment of the device's algorithmic and sensing accuracy without human intervention for interpretation beyond what the user does with the displayed values.
7. The Type of Ground Truth Used:
The ground truth used was laboratory reference measurements ("reference venous plasma sample YSI measurements").
8. The Sample Size for the Training Set:
The document does not provide any information about the training set size for the algorithms within the Stelo Glucose Biosensor System. This information is typically not included in a 510(k) summary unless the submission is for an AI/ML SaMD where the training data characteristics are a primary focus. Given that the Stelo System uses the "same hardware design as the predicate G7 CGM System" and its GSS firmware is designed to support a "factory-calibrated only device (without calibration inputs)," it suggests that the core algorithms might have been trained previously and validated, or leveraged from the predicate device's development.
9. How the Ground Truth for the Training Set Was Established:
This information is not provided in the document.
§ 862.1355 Integrated continuous glucose monitoring system.
(a)
Identification. An integrated continuous glucose monitoring system (iCGM) is intended to automatically measure glucose in bodily fluids continuously or frequently for a specified period of time. iCGM systems are designed to reliably and securely transmit glucose measurement data to digitally connected devices, including automated insulin dosing systems, and are intended to be used alone or in conjunction with these digitally connected medical devices for the purpose of managing a disease or condition related to glycemic control.(b)
Classification. Class II (special controls). The special controls for this device are:(1) Design verification and validation must include the following:
(i) Robust clinical data demonstrating the accuracy of the device in the intended use population.
(ii) The clinical data must include a comparison between iCGM values and blood glucose values in specimens collected in parallel that are measured on an FDA-accepted laboratory-based glucose measurement method that is precise and accurate, and that is traceable to a higher order (
e.g., an internationally recognized reference material and/or method).(iii) The clinical data must be obtained from a clinical study designed to fully represent the performance of the device throughout the intended use population and throughout the measuring range of the device.
(iv) Clinical study results must demonstrate consistent analytical and clinical performance throughout the sensor wear period.
(v) Clinical study results in the adult population must meet the following performance requirements:
(A) For all iCGM measurements less than 70 milligrams/deciliter (mg/dL), the percentage of iCGM measurements within ±15 mg/dL of the corresponding blood glucose value must be calculated, and the lower one-sided 95 percent confidence bound must exceed 85 percent.
(B) For all iCGM measurements from 70 mg/dL to 180 mg/dL, the percentage of iCGM measurements within ±15 percent of the corresponding blood glucose value must be calculated, and the lower one-sided 95 percent confidence bound must exceed 70 percent.
(C) For all iCGM measurements greater than 180 mg/dL, the percentage of iCGM measurements within ±15 percent of the corresponding blood glucose value must be calculated, and the lower one-sided 95 percent confidence bound must exceed 80 percent.
(D) For all iCGM measurements less than 70 mg/dL, the percentage of iCGM measurements within ±40 mg/dL of the corresponding blood glucose value must be calculated, and the lower one-sided 95 percent confidence bound must exceed 98 percent.
(E) For all iCGM measurements from 70 mg/dL to 180 mg/dL, the percentage of iCGM measurements within ±40 percent of the corresponding blood glucose value must be calculated, and the lower one-sided 95 percent confidence bound must exceed 99 percent.
(F) For all iCGM measurements greater than180 mg/dL, the percentage of iCGM measurements within ±40 percent of the corresponding blood glucose value must be calculated, and the lower one-sided 95 percent confidence bound must exceed 99 percent.
(G) Throughout the device measuring range, the percentage of iCGM measurements within ±20 percent of the corresponding blood glucose value must be calculated, and the lower one-sided 95 percent confidence bound must exceed 87 percent.
(H) When iCGM values are less than 70 mg/dL, no corresponding blood glucose value shall read above 180 mg/dL.
(I) When iCGM values are greater than 180 mg/dL, no corresponding blood glucose value shall read less than 70 mg/dL.
(J) There shall be no more than 1 percent of iCGM measurements that indicate a positive glucose rate of change greater than 1 mg/dL per minute (/min) when the corresponding true negative glucose rate of change is less than −2 mg/dL/min as determined by the corresponding blood glucose measurements.
(K) There shall be no more than 1 percent of iCGM measurements that indicate a negative glucose rate of change less than −1 mg/dL/min when the corresponding true positive glucose rate of change is greater than 2 mg/dL/min as determined by the corresponding blood glucose measurements.
(vi) Data demonstrating similar accuracy and rate of change performance of the iCGM in the pediatric population as compared to that in the adult population, or alternatively a clinical and/or technical justification for why pediatric data are not needed, must be provided and determined by FDA to be acceptable and appropriate.
(vii) Data must demonstrate that throughout the claimed sensor life, the device does not allow clinically significant gaps in sensor data availability that would prevent any digitally connected devices from achieving their intended use.
(2) Design verification and validation must include a detailed strategy to ensure secure and reliable means of iCGM data transmission to provide real-time glucose readings at clinically meaningful time intervals to devices intended to receive the iCGM glucose data.
(3) Design verification and validation must include adequate controls established during manufacturing and at product release to ensure the released product meets the performance specifications as defined in paragraphs (b)(1) and (b)(2) of this section.
(4) The device must demonstrate clinically acceptable performance in the presence of clinically relevant levels of potential interfering substances that are reasonably present in the intended use population, including but not limited to endogenous substances and metabolites, foods, dietary supplements, and medications.
(5) The device must include appropriate measures to ensure that disposable sensors cannot be used beyond its claimed sensor wear period.
(6) Design verification and validation must include results obtained through a usability study that demonstrates that the intended user can use the device safely and obtain the expected glucose measurement accuracy.
(7) The labeling required under § 809.10(b) of this chapter must include a separate description of the following sensor performance data observed in the clinical study performed in conformance with paragraph (b)(1) of this section for each intended use population, in addition to separate sensor performance data for each different iCGM insertion or use sites (
e.g., abdomen, arm, buttock):(i) A description of the accuracy in the following blood glucose concentration ranges: less than 54 mg/dL, 54 mg/dL to less than 70 mg/dL, 70 to 180 mg/dL, greater than 180 to 250 mg/dL, and greater than 250 mg/dL.
(ii) A description of the accuracy of positive and negative rate of change data.
(iii) A description of the frequency and duration of gaps in sensor data.
(iv) A description of the true, false, missed, and correct alert rates and a description of the available glucose concentration alert settings, if applicable.
(v) A description of the observed duration of iCGM life for the device.