(54 days)
Microlife Digital Underarm Thermometer MT18E1 V932 is designed specifically for measuring underarm (axillary) temperatures in children ages infant to 6 years old.
Unlike regular thermometers, the unique elbow of the Digital Underarm thermometer is designed to find the " hotspot" easily and comfortably every time. In addition, to speed up the measurement time, we have added the fixed offset into this thermometer which is fulfilled by the hardware. With these characteristics, this thermometer can provide both a very high clinical accuracy and quick measurement time.
The basic principle of this thermometer is that change of thermistor resistance, caused by changes of temperature, are converted to changes of frequency of R-C oscillator circuit. Therefore, temperature can be given by measuring the frequency of oscillator.
The thermometer uses a clinical offset of 1.5°F to match the actual underarm temperature.
The provided text describes the 510(k) summary for the Microlife Digital Underarm Electronic Thermometer, Model MT18E1 (V932). However, it does not contain the detailed information necessary to fully answer all aspects of your request regarding acceptance criteria and the comprehensive study that proves the device meets those criteria.
Here's an breakdown of what can be extracted and what is missing:
1. Table of Acceptance Criteria and Reported Device Performance:
The document mentions compliance with ASTM E1112 as an applicable voluntary standard. This standard would contain the acceptance criteria for electronic thermometers. However, the specific criteria (e.g., accuracy range, measurement time) and the device's reported performance against those specific criteria are not explicitly stated in the provided text. It only generally states that clinical data was presented evaluating "clinical bias, clinical uncertainty, clinical repeatability and clinical offset."
| Acceptance Criteria (from ASTM E1112 - not explicitly stated in document, inferred) | Reported Device Performance (as stated or inferred) |
|---|---|
| (Specific accuracy limits, e.g., ±X°F for Y temperature range) | "very high clinical accuracy" (general statement) |
| (Specific measurement time limits) | "quick measurement time" (general statement) |
| (Clinical bias, uncertainty, repeatability limits) | Clinical data presented evaluating clinical bias, clinical uncertainty, clinical repeatability, and clinical offset. (Specific values not provided) |
2. Sample Size Used for the Test Set and Data Provenance:
- Sample Size: Not specified. The document states "Controlled human clinical studies were conducted," but the number of subjects or measurements is not provided.
- Data Provenance: The studies were "Controlled human clinical studies" but the geographic location (e.g., country of origin) and whether they were retrospective or prospective are not specified. Given the nature of clinical trials for device approval, they are typically prospective.
3. Number of Experts Used to Establish Ground Truth and Qualifications:
Not specified. The document mentions "Controlled human clinical studies" and that clinical data was presented, but it does not detail how ground truth temperatures were established, nor the involvement or qualifications of experts.
4. Adjudication Method for the Test Set:
Not specified. The document does not mention any adjudication method.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
Not applicable/Not done. This type of study (MRMC) is typically used for imaging modalities or diagnostics where multiple human readers interpret cases. A digital thermometer measures a physiological parameter directly, so an MRMC study comparing human "reading" of the thermometer with and without AI assistance is not relevant to this device. The device itself is the "reader."
6. Standalone Performance Study (Algorithm only without human-in-the-loop):
Yes, implicitly. The clinical studies conducted evaluate the performance of the "Microlife Digital Underarm thermometer MT18E1 V932" as a standalone device. Its output (temperature reading) is the direct result of the device's algorithm and hardware, without requiring human interpretation or intervention in the measurement process itself. The "clinical bias, clinical uncertainty, clinical repeatability and clinical offset" are all measures of standalone performance.
7. Type of Ground Truth Used:
Inferred to be reference temperature measurement. For a thermometer, the "ground truth" would typically be established by a highly accurate reference thermometer or method (e.g., rectal temperature using a laboratory-grade precision thermometer, or core body temperature measured invasively if ethical and feasible). The document does not explicitly state the method, but for evaluating "clinical bias, clinical uncertainty, clinical repeatability and clinical offset," a reference standard is used for comparison.
8. Sample Size for the Training Set:
Not applicable/Not specified. This device is a digital thermometer, not an AI/ML model that requires a "training set" in the conventional sense of machine learning for image classification or prediction tasks. While the device's offset of 1.5°F is "fixed" and integrated into the hardware, this would have been determined through empirical testing and calibration, not through a "training set" like an AI algorithm.
9. How the Ground Truth for the Training Set was Established:
Not applicable/Not specified. As noted above, there's no "training set" in the AI/ML sense. The "fixed offset into this thermometer which is fulfilled by the hardware" implies that the 1.5°F offset was determined through prior empirical testing and comparison to reference temperatures to align underarm readings with actual core or reference body temperatures. The document does not detail how that 1.5°F offset was established or the ground truth used for that determination.
§ 880.2910 Clinical electronic thermometer.
(a)
Identification. A clinical electronic thermometer is a device used to measure the body temperature of a patient by means of a transducer coupled with an electronic signal amplification, conditioning, and display unit. The transducer may be in a detachable probe with or without a disposable cover.(b)
Classification. Class II (performance standards). The device is exempt from the premarket notification procedures in part 807, subpart E of this chapter, subject to the limitations in § 880.9 and the following conditions for exemption:(1) Device is not a clinical thermometer with telethermographic functions;
(2) Device is not a clinical thermometer with continuous temperature measurement functions; and
(3) Appropriate analysis and testing (such as that outlined in the currently FDA-recognized editions, as appropriate, of ISO 80601-2-56, “Medical electrical equipment—Part 2-56: Particular requirements for basic safety and essential performance of clinical thermometers for body temperature measurement,” or ASTM E1965, “Standard Specification for Infrared Thermometers for Intermittent Determination of Patient Temperature,” or ASTM E1112, “Standard Specification for Electronic Thermometer for Intermittent Determination of Patient Temperature,” or ASTM E1104, “Standard Specification for Clinical Thermometer Probe Covers and Sheaths”) must validate specifications and performance of the device.