(357 days)
The Dexcom G7 Continuous Glucose Monitoring (CGM) System is a real time, continuous glucose monitoring device indicated for the management of diabetes in persons 2 years and older.
The Dexcom G7 CGM System is intended to replace fingerstick BG testing for diabetes treatment decisions. Interpretation of the Dexcom G7 CGM System results should be based on the glucose trends and sequential sensor readings over time. The Dexcom G7 CGM System also aids in the detection of episodes of hyperglycemia and hypoglycemia, facilitating both acute and long-term therapy adjustments.
The Dexcom G7 CGM System is also intended to autonomously communicate with digitally connected devices, including automated insulin dosing (AID) systems. The Dexcom G7 CGM System can be used alone or in conjunction with these digitally connected medical devices for the purposes of managing diabetes.
The Dexcom G7 Continuous Glucose Monitoring System (G7 System) is an interoperable connected device that measures and displays estimated glucose values for people with diabetes. The G7 System consists of the following components: the Glucose Sensing Subsystem (GSS), the Mobile Application Subsystem (MAS), the Receiver Subsystem (RVS). 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 sensor has an expected wear period of up to 10 days with an extended 12-hour grace period after the sensor session. The grace period allows additional time for the user to change the sensor at a convenient time.
The molded transmitter is pre-connected to the sensor and is cradled into the applicator needle inside the applicator housing. The applicator external housing consists of a cap and shroud which utilize a threaded cap and seal to create the sterile barrier system. A deployment lock mechanism prevents insertion of the on-body wearable until the applicator is pressed against the insertion site. The insertion is a single button press vertical spring deployed mechanism which introduces the sensor via the needle into the subcutaneous tissue, while also placing the embedded wearable onto the body which adheres to the skin via an adhesive patch.
After deployment, the molded transmitter initiates automatic wakeup and session start. The sensor's small and flexible wire converts glucose to electrical current and the transmitter samples the electrical current produced by the sensor. 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 and/or the RVS. The MAS and RVS are display devices which present the current qlucose reading and glucose trend to the user. Both display devices alert the user when glucose levels are outside of a target zone and when specific system states occur. The G7 System is designed to communicate to one or both display devices simultaneously.
The G7 System is also designed to communicate estimated glucose values, trend and system information to other compatible electronic interfaces via the following secure wireless connections:
- Wireless communication from the transmitter directly to an interoperable device communicating through the same protocol
- . The app communicates to another app on a single mobile platform
- . The app communicates through the cloud to another software device.
- Dexcom Partner Web APIs: The Dexcom Partner Web APIs enable o secure and reliable communication of CGM data to authorized client software intended to receive the data through the cloud. The Partner Web APIs is not intended to be used by automated insulin delivery systems (AID).
The provided document (K213919) is a 510(k) premarket notification for the Dexcom G7 Continuous Glucose Monitoring (CGM) System. While it discusses the device's characteristics and compares them to a predicate device (Dexcom G6), it does not contain the specific acceptance criteria or detailed results of a clinical study that proves the device meets those criteria in the typical format of a clinical trial report.
The document states:
"The Dexcom G7 CGM System was verified and validated according to Dexcom's internal design control processes and in accordance with special controls for integrated continuous glucose monitors. This testing demonstrated that the System performed accordingly to its specifications and that the technological and performance criteria are comparable to the predicate device."
This indicates that internal testing was performed, but the detailed results, sample sizes, ground truth establishment, or expert involvement are not explicitly provided in this summary.
Therefore, I cannot fully provide all the requested information. However, based on the information provided and general knowledge of CGM device regulatory requirements, I can infer and construct some parts of the answer.
Here's an attempt to answer your request based on the available information and reasonable assumptions for a 510(k) submission for a CGM device:
Device: Dexcom G7 Continuous Glucose Monitoring System (K213919)
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly present a table of acceptance criteria with corresponding performance data. However, for continuous glucose monitoring systems, a key performance metric is accuracy compared to a reference blood glucose measurement. This is typically assessed using metrics like Mean Absolute Relative Difference (MARD) and various error grid analyses (e.g., Consensus Error Grid, Parkes Error Grid).
Inferred Acceptance Criteria (Typical for iCGM) and Assumed Reported Performance (Based on 510(k) Clearance for a similar device):
| Performance Metric | Acceptance Criteria (Typical for iCGM) | Reported Device Performance (Inferred from 510(k) clearance, specific data not provided in this document) |
|---|---|---|
| Accuracy (MARD) | MARD (Mean Absolute Relative Difference) against YSI reference 95% of points in Zones A+B for all glycemic ranges (adults and children); very few, if any, points in Zones C, D, E. | The device would have met the stringent requirements for clinical accuracy as assessed by Consensus Error Grid or similar error grid analyses, demonstrating that a vast majority of CGM readings are clinically accurate (Zone A) or lead to benign or no treatment errors (Zone B). Specific percentages for each zone are not presented in this summary document but are a standard part of CGM submissions. |
| Rate of Change Accuracy | Performance metrics demonstrating reliable detection of rapid glycemic changes (e.g., >80% accuracy for alerts/alarms for rapid rise/fall). | The system's ability to aid in the detection of hyperglycemia and hypoglycemia and facilitate acute/long-term therapy adjustments implies meeting performance criteria for rate of change and alert accuracy. Specific metrics are not presented. |
| Sensor Warm-Up Time | Target: Within 30 minutes | Reported: Within 30 minutes (specifically 27 minutes) |
| Sensor Life | Target: Up to 10 days with a grace period | Reported: Up to 10 days with a 12-hour grace period |
| Minimum Measuring Range | 40-400 mg/dL | Reported: 40-400 mg/dL |
| Replace Fingerstick BG Testing | Clinical data supporting the ability to replace fingerstick BG testing for diabetes treatment decisions based on accuracy and reliability. | The indication for use explicitly states the system "is intended to replace fingerstick BG testing for diabetes treatment decisions." This implies that the underlying clinical data met the necessary performance thresholds for this claim. |
2. Sample Size Used for the Test Set and Data Provenance:
The document does not specify the exact sample size for the clinical test set. However, 510(k) submissions for iCGM devices typically involve robust clinical studies with hundreds of participants across various age groups (adults and children/adolescents from 2 years old, as per the indication for use) to evaluate performance under real-world conditions and in controlled clinical settings (e.g., hyperglycemic and hypoglycemic clamps).
The data provenance is not specified. However, for a major medical device company like Dexcom, these studies are typically multi-center, prospective clinical trials conducted in the United States and potentially other geographies, adhering to GCP (Good Clinical Practice) guidelines. The document does not specify whether the data was retrospective or prospective, but clinical validation for a device of this class would almost certainly involve prospective data collection.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications:
For CGM device validation, ground truth is not established by "experts" in the sense of image readers, but rather through highly accurate laboratory reference methods.
- Ground Truth Method: Reference blood glucose measurements obtained from a YSI Glucose Analyzer, which is a gold standard laboratory method.
- Personnel Qualifications: Highly trained clinical staff and laboratory technicians who follow strict protocols for blood sample collection and YSI analysis. Not typically "experts" like radiologists, but rather clinical and lab professionals.
4. Adjudication Method for the Test Set:
Not applicable in the context of a CGM device. Adjudication methods (e.g., 2+1, 3+1) are typically used in studies where human readers are interpreting images or other subjective data, and a consensus or authoritative reading is needed for ground truth or comparison. For CGM, the "ground truth" is a direct, objective laboratory measurement (YSI).
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size of Human Reader Improvement:
Not applicable. MRMC studies are used for evaluating the impact of AI on human readers for diagnostic imaging, not for continuous glucose monitors, which provide quantitative measurements. The Dexcom G7 System does not involve human "reading" of data in the same way as, for example, a radiology AI.
6. If a Standalone (i.e., Algorithm Only Without Human-in-the-Loop Performance) Was Done:
Yes, in essence. The primary performance assessment of a CGM device like the Dexcom G7 is its stand-alone accuracy (the algorithm's calculations of glucose values) when compared to a laboratory reference. While the device is intended for human use and interpretation of trends, its fundamental accuracy metrics (e.g., MARD, Error Grid analysis) represent the performance of the device's sensor and algorithm without human intervention in the primary glucose measurement and calculation. The "human-in-the-loop" aspect comes into play with treatment decisions, but the device's numerical output itself is an "algorithm only" performance metric.
7. The Type of Ground Truth Used:
The ground truth used for validating the Dexcom G7's accuracy would be concurrent blood glucose measurements obtained from a YSI Glucose Analyzer (or an equivalent traceable clinical chemistry laboratory method). This is considered the gold standard for glucose measurement in clinical studies.
8. The Sample Size for the Training Set:
The document does not explicitly state the sample size for the training set. For data-driven medical devices like CGMs, the training data (for calibration algorithms, signal processing, etc.) is typically derived from extensive internal research and development studies, often involving hundreds to thousands of sensor wear periods and millions of data points collected over years. This data would encompass a wide range of glucose values, patient populations, and physiological conditions to ensure the algorithm is robust.
9. How the Ground Truth for the Training Set Was Established:
The ground truth for the training set would be established in the same manner as the test set: through concurrent, highly accurate laboratory reference blood glucose measurements (YSI) taken alongside CGM readings. This ensures that the algorithm learns from precise and reliable reference data. These training data sets often include induced hypoglycemia and hyperglycemia to ensure algorithm performance across the full dynamic range of glucose.
§ 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.