(172 days)
Libre 2 Sensor users:
The FreeStyle Libre 2 Flash Glucose Monitoring System is a continuous glucose monitoring (CGM) device with real time alarms capability indicated for the management of diabetes in persons age 4 and older. It is intended to replace blood glucose testing for diabetes treatment decisions, unless otherwise indicated.
The System also detects trends and tracks patterns and aids in the detection of episodes of hyperglycemia and hypoglycemia, facilitating both acute and long-term therapy adjustments. Interpretation of the System readings should be based on the glucose trends and several sequential readings over time.
The System is also intended to autonomously communicate with digitally connected devices. The System can be used alone or in conjunction with these digitally connected devices where the user manually controls actions for therapy decisions.
Libre 2 Plus Sensor users:
The FreeStyle Libre 2 Flash Glucose Monitoring System is a continuous glucose monitoring (CGM) device with real time alarms capability indicated for the management of diabetes in persons age 2 and older. It is intended to replace blood glucose testing for diabetes treatment decisions, unless otherwise indicated.
The System also detects trends and tracks patterns and aids in the detection of episodes of hyperglycemia and hypoglycemia, facilitating both acute and long-term therapy adjustments. Interpretation of the System readings should be based on the glucose trends and several sequential readings over time.
The System is also intended to autonomously communicate with digitally connected devices, including automated insulin dosing (AID) systems. The System can be used alone or in conjunction with these digitally connected devices for the purpose of managing diabetes.
Libre 3 Sensor users:
The FreeStyle Libre 3 Continuous Glucose Monitoring System is a real time continuous glucose monitoring (CGM) device with alarms capability indicated for the management of diabetes in persons age 4 and older. It is intended to replace blood glucose testing for diabetes treatment decisions, unless otherwise indicated.
The System also detects trends and tracks patterns and aids in the detection of episodes of hyperglycemia and hypoglycemia, facilitating both acute and long-term therapy adjustments. Interpretation of the System readings should be based on the glucose trends and several sequential readings over time.
The System is also intended to autonomously communicate with digitally connected devices. The System can be used alone or in conjunction with these digitally connected devices where the user manually controls actions for therapy decisions.
Libre 3 Plus Sensor users:
The FreeStyle Libre 3 Continuous Glucose Monitoring System is a real time continuous glucose monitoring (CGM) device with alarms capability indicated for the management of diabetes in persons age 2 and older. It is intended to replace blood glucose testing for diabetes treatment decisions, unless otherwise indicated.
The System also detects trends and tracks patterns and aids in the detection of episodes of hyperglycemia and hypoglycemia, facilitating both acute and long-term therapy adjustments. Interpretation of the System readings should be based on the glucose trends and several sequential readings over time.
The System is also intended to autonomously communicate with digitally connected devices, including automated insulin dosing (AID) systems. The System can be used alone or in conjunction with these digitally connected devices for the purpose of managing diabetes.
The FreeStyle Libre 3 Continuous Glucose Monitoring System (hereinafter also referred to as 'FSL3 System') and FreeStyle Libre 2 Flash Glucose Monitoring System (hereinafter also referred to as the 'FSL2 System') are integrated continuous glucose monitoring (iCGM) systems that provide continuous glucose measurements every minute to provide glucose levels, trends, and real-time alarms capability to aid in the management of diabetes. The FSL2 and FSL3 Systems also provide configurable alarms designed to warn the user of Low Glucose, High Glucose or Signal Loss. The user may make treatment decisions based in part on the sensor glucose results provided by both Systems. The FSL2 and FSL3 Systems require a prescription and are intended for home use.
The subject FSL3 System consists of a sensor (the FreeStyle Libre 3 Sensor (FSL3 Sensor) or FreeStyle Libre 3 Plus Sensor (FSL3 Plus Sensor)) and a primary display device (the FreeStyle Libre 3 Reader (FSL3 Reader) or the FreeStyle Libre App (FSL App) [iOS and Android] downloaded to a compatible phone). The FSL3 Reader and the FSL App do not interact with each other.
The subject FSL2 System consists of a sensor (the FreeStyle Libre 2 Sensor (FSL2 Sensor) or FreeStyle Libre 2 Plus Sensor (FSL2 Plus Sensor)) and a primary display device (the FreeStyle Libre 2 Reader (FSL2 Reader) or the FSL App (iOS and Android) downloaded to a compatible phone). The FSL2 Reader and FSL App do not interact with each other.
Both the FSL2 and FSL3 Systems are compatible with the Libre Data Sharing API cleared in K223537. The display device of the connected FSL2 or FSL3 Systems, which directly receives the data from the sensor, continues to serve as a primary display device for the glucose data and alarms.
This document is a 510(k) summary from Abbott Diabetes Care Inc. regarding their FreeStyle Libre 3 Continuous Glucose Monitoring System and FreeStyle Libre 2 Flash Glucose Monitoring System. It outlines the device details, indications for use, comparison to predicate devices, and a summary of performance testing.
Acceptance Criteria and Study Proving Device Meets Criteria
The provided text focuses on the substantial equivalence of the new FreeStyle Libre 2 Plus and 3 Plus sensors and updated app features to their predicate devices, rather than establishing new acceptance criteria for the entire system's glucose monitoring accuracy. The document states that clinical performance and human factors were "established in the predicate device (K223435) and are not affected by the introduction of the FSL App in this 510(k)." This implies that the glucose accuracy and user interface performance metrics (e.g., MARD, % in Zones A+B, usability outcomes) for the core glucose monitoring function were previously accepted for the predicate devices and are assumed to hold true for the current submission due to the nature of the changes being primarily related to sensor life, age ranges, and app features.
Therefore, the acceptance criteria and performance data discussed below are extrapolated from the types of performance studies conducted to demonstrate substantial equivalence for the modifications presented in this 510(k), particularly regarding safety and compatibility, and from the implied reliance on the predicate device's established clinical performance.
Please note: This response does not contain specific quantitative acceptance criteria or precise performance metrics for glucose accuracy (e.g., MARD values) as these details are explicitly referred to as having been established in the predicate device (K223435) and are not re-evaluated in this submission. The focus of this 510(k) is on the changes from the predicate.
1. Table of Acceptance Criteria and Reported Device Performance
Given the nature of this 510(k) (modifications to existing systems), the presented "acceptance criteria" are derived from the tests conducted to demonstrate that the changes do not adversely affect safety and effectiveness.
| Category | Specific Test/Feature | Acceptance Criteria (Implied/Stated) | Reported Device Performance/Conclusion |
|---|---|---|---|
| Software | Software Verification and Validation | Compliant with IEC 62304 and FDA Guidance "Content of Premarket Submissions for Device Software Functions" (June 14, 2023) and "Multiple Function Device Products: Policy and Considerations" (July 29, 2020). | Results of executed protocols met the acceptance criteria and therefore support that the system software is acceptable for its intended use. |
| Cybersecurity | Cybersecurity Risk Management | Compliant with FDA guidance "Cybersecurity in Medical Devices: Quality System Considerations and Content of Premarket Submissions'' (September 27, 2023). Appropriate risk mitigation for identified threats and vulnerabilities. | Risk assessment performed, appropriate risk mitigation controls implemented and tested. |
| Bench Testing | Removal of CT/MRI Contraindications, X-ray Caution | Functionality testing acceptance criteria met for sensor performance after exposure to CT, MRI (MR conditional), and X-ray. | The test results showed all functionality testing acceptance criteria was met. (Previous mechanical, electrical, and functional testing established in the predicate device are not affected). |
| App Feature: Auto-Display (FSL2) | Automatic display of glucose results without user-initiated scan. | Functionality: Glucose data automatically displays via BLE without user scan, while NFC scan option remains. | Functionality confirmed. (Users may still perform NFC scan as an option, consistent with predicate FSL2 App behavior.) |
| App Feature: Alarms Escalation | Incremental volume increase for alarms (High, Low, Urgent Low, Signal Loss). | Volume increases incrementally over 30 seconds until maximum volume, equal to predicate device alarm volume. | Functionality confirmed: Alarms increase volume over 30 seconds to the maximum level of predicate device alarms. |
| Core Glucose Monitoring Performance | Clinical Performance (e.g., Accuracy) | Established in predicate device K223435. (No new evaluation specified in this 510(k) summary for these aspects). | Established in the predicate device (K223437) and not affected by the introduction of the FSL App in this 510(k). (This implies that the existing performance data from K223435 is deemed sufficient for these modified devices). |
| Human Factors | Usability and User Interface (new features) | Established in predicate device K223435. (No new evaluation specified in this 510(k) summary for these aspects beyond software V&V). | Established in the predicate device (K223437) and not affected by the introduction of the FSL App in this 510(k). (The app navigation change to "Bottom bar navigation menu" from "Side panel navigation", and the "App Stopped Alarm" for Android were likely part of software V&V and user acceptance testing, implied by overall software V&V acceptance). |
2. Sample Size Used for the Test Set and Data Provenance
The document does not provide specific sample sizes for the detailed technical tests (Software V&V, Cybersecurity, Bench Testing for CT/MRI/X-ray). These types of tests typically involve controlled laboratory environments rather than human subject test sets in the traditional sense for clinical performance.
For the core clinical performance (glucose accuracy, etc.), the document explicitly states these characteristics were "established in the predicate device (K223435) and are not affected." Therefore, any sample size for these fundamental performance aspects would refer to those used in the studies for the predicate device, which are not detailed in this 510(k) summary.
Data Provenance: The document does not specify the country of origin for any testing data. The nature of the tests (Software V&V, Cybersecurity, Bench Testing) suggests they are likely conducted in a controlled environment, potentially in-house or by a certified testing facility. The "retrospective or prospective" nature is not specified, but these are typically prospective tests conducted as part of the development and verification process.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
This type of information (number of experts, qualifications, and ground truth establishment) is typically relevant for clinical studies involving expert adjudication (e.g., for diagnostic imaging devices). Given that the 510(k) summary indicates clinical performance was "established in the predicate device" and that the current submission primarily addresses technical and software improvements/modifications, there's no mention of a new clinical study involving multiple experts to establish ground truth for this specific submission.
For the bench testing related to CT/MRI/X-ray compatibility, ground truth would be established by physical measurements and functional checks against engineering specifications, not by human experts.
4. Adjudication Method for the Test Set
Adjudication methods (e.g., 2+1, 3+1) are typically used in clinical studies, particularly for diagnostic accuracy where multiple human readers interpret data. As explained above, this 510(k) focuses on technical and software changes, and refers back to the predicate device for clinical performance. Therefore, no information on an adjudication method for a test set is provided or expected in this context.
5. If a Multi Reader Multi Case (MRMC) Comparative Effectiveness Study was done
No, an MRMC comparative effectiveness study was not done, and it is not typically relevant for a CGM device. MRMC studies are primarily conducted for diagnostic imaging devices to assess how AI assistance impacts human reader performance (e.g., radiologists interpreting scans). CGM devices provide quantitative glucose measurements, and their performance is evaluated directly against a reference method (e.g., laboratory glucose measurements), not through human reader interpretation of complex images or cases.
6. If a Standalone (i.e. algorithm only without human-in-the loop performance) was done
Yes, for the core glucose algorithm, a standalone performance evaluation is inherent to a CGM device. The document explicitly states:
- Glucose Algorithm: "ADC Glucose Algorithm"
- Location of Glucose Algorithm: "FSL2 System: Receiver", "FSL3 System: Sensor"
This implies that the algorithm processes the sensor's raw electrical signals to calculate a glucose value and trend independently. The clinical performance of this algorithm (e.g., MARD against a reference method) would have been part of the studies for the predicate device (K223435). This 510(k) does not present new data for this, but rather relies on the predicate's established performance, stating that ADC (Abbott Diabetes Care) Glucose Algorithm is the "Same" for the subject device.
7. The Type of Ground Truth Used
For Continuous Glucose Monitoring (CGM) devices, the ground truth for establishing accuracy is typically obtained from laboratory reference methods for blood glucose concentration, such as:
- YSI analysis (Yellow Springs Instrument): This is a widely accepted laboratory reference method for measuring glucose in blood or plasma samples.
While not explicitly stated in this 510(k) summary for the ground truth method, it is the standard for CGM accuracy studies which would have been performed for the predicate device to which this submission refers for clinical performance.
8. The Sample Size for the Training Set
The document does not provide a sample size for the training set of the glucose algorithm. This information would typically be detailed in the original predicate device's submission which established the clinical performance. The current 510(k) refers to the "ADC Glucose Algorithm" as being the same as the predicate, indicating no retraining or significant algorithm changes that would necessitate reporting new training data.
9. How the Ground Truth for the Training Set was Established
Similar to the sample size, the specifics of how the ground truth was established for the training set would have been detailed in the original submission for the predicate device. For CGM algorithms, this involves comparing the sensor's raw electrical signals to paired blood glucose values obtained from a highly accurate laboratory reference method (like YSI), collected over time from a cohort of study participants under various glycemic conditions. This establishes the true glucose concentration against which the algorithm learns to convert sensor signals into accurate glucose readings.
§ 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.