(122 days)
The LifeGuard and BacTrack B90 devices are intended to measure alcohol in human breath. Measurements obtained from these devices are used in the diagnosis of alcohol intoxication.
The LifeGuard and BacTrack B90 devices are intended to be used by the general adult population and by qualified personnel, such as physicians, nurses, and technicians.
The LifeGuard and BacTrack B90 devices are intended to be used by adults (age 21 and over) in measuring alcohol intoxication in themselves or others.
The LifeGuard and BacTrack B90 devices are intended to be used in both home (over-the-counter) and clinical settings.
The LifeGuard product is a breath alcohol detector designed to sample the patient's deep lung air in order to test for the presence of alcohol in the blood. The sensor used in the LifeGuard is an electrochemical fuel cell sensor. When the patient exhales into the device, after 4 seconds a sample of the breath is pumped into the fuel cell and generates an electrical current. The amount and duration of the current has a known relationship to the concentration of alcohol in the breath sample. The relationship between the alcohol concentration in the deep lung breath and in the blood is known by Henry's law with a ratio of 2100:1.
The BacTrack B90 has the same intended use, description and performance characteristics as the LifeGuard with a different physical appearance.
Both the LifeGuard and BacTrack B90 products are handheld and are used with a single-use disposable mouthpiece and a replaceable 9 volt battery.
Here's an analysis of the provided text regarding the LifeGuard and BacTrack B90 devices, focusing on the acceptance criteria and the study that proves they meet those criteria:
1. Table of Acceptance Criteria and Reported Device Performance:
The primary acceptance criterion mentioned is accuracy. The device's performance is directly compared to its predicates.
| Acceptance Criteria | LifeGuard / BacTrack B90 Performance | Predicate 1 (Drager 6510) Performance | Predicate 2 (AlcoHawk PT-500) Performance |
|---|---|---|---|
| Accuracy | +/-.005 BAC from 0 to .100 BAC. +/- 5% above .100 BAC | From 0 to 0.5 mg/l +/- .008 mg/l (approx. +/-.00168 BAC); above 0.5 mg/l +/- 1.7% of measured volume | +/- 0.005 BAC at .050 BAC |
| Measuring Range | .000 to .400 BAC | .000 to .500 BAC | 0.000-0.400 BAC |
| Compliance with Safety Standards | Compliance with applicable US and European safety standards for a medical device | (Implied for cleared predicate) | (Implied for cleared predicate) |
| Meeting User Requirements/Labeling Adequacy | Met requirements of users and labeling adequate for proper use | (Implied for cleared predicate) | (Implied for cleared predicate) |
2. Sample Size Used for the Test Set and Data Provenance:
The document mentions "laboratory bench testing" and "user studies,". However, specific sample sizes for the test set or information on data provenance (e.g., country of origin, retrospective/prospective) are NOT provided in the given text.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications:
The document does not provide information on the number or qualifications of experts used to establish ground truth for the test set.
4. Adjudication Method for the Test Set:
The document does not specify any adjudication method (e.g., 2+1, 3+1, none) for the test set.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size:
No Multi-Reader Multi-Case (MRMC) comparative effectiveness study is mentioned. This device is a breathalyzer, so the concept of "human readers" interpreting images with and without AI assistance is not applicable. The device provides a direct measurement.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done:
The "laboratory bench testing" described for the device would represent its standalone performance, as it verifies the hardware and firmware performance against specifications. However, the exact details of this testing (e.g., specific algorithms or human intervention) are not extensively detailed, beyond its function as a breath alcohol detector.
7. The Type of Ground Truth Used:
For the accuracy testing, the ground truth would likely be established by a calibrated alcohol standard or controlled human breath samples with known alcohol concentrations. While not explicitly stated, this is the standard method for establishing ground truth in breath alcohol measurement devices. The document implies this through the accuracy claims. The statement "The relationship between the alcohol concentration in the deep lung breath and in the blood is known by Henry's law with a ratio of 2100:1" indicates the scientific basis for the measurement, further implying a quantitative ground truth for alcohol concentration.
8. The Sample Size for the Training Set:
The document does not provide any information regarding a training set or its sample size. This type of device relies on a fixed scientific principle (electrochemical fuel cell and Henry's law) rather than machine learning algorithms that typically require large training datasets.
9. How the Ground Truth for the Training Set Was Established:
As there's no mention of a training set in the context of machine learning, this question is not applicable. The device's underlying principle is a direct chemical measurement, not a learned model from data. The device's 'training' or calibration would be through manufacturing processes and in-field calibration against known alcohol standards.
Summary of Study Details Provided in the Text:
The text states that the device meets acceptance criteria through:
- Laboratory bench testing: To verify hardware and firmware performance against specifications. This would explicitly test accuracy and other technical parameters.
- NRTL safety testing: To certify compliance with US and European safety standards.
- User studies: To validate that the device met user requirements and that labeling was adequate.
The conclusion asserts that "the LifeGuard design, feature set, verification and validation results, and agency testing reports demonstrate that the LifeGuard breath alcohol tester is a safe, effective product that is substantially equivalent to other FDA cleared alcohol breath testing products." This implies that the tests conducted were sufficient to demonstrate equivalence in terms of safety and effectiveness to the predicate devices, particularly in the realm of accuracy.
§ 862.3050 Breath-alcohol test system.
(a)
Identification. A breath-alcohol test system is a device intened to measure alcohol in the human breath. Measurements obtained by this device are used in the diagnosis of alcohol intoxication.(b)
Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 862.9.