(228 days)
Infrared Thermometer is a reusable thermometer intended for the intermittent determination of human body temperature in a non-contact mode using the center of the forehead as the measurement site on people of all ages. It can be used by consumers in the household environment and by healthcare provider.
The infrared thermometer uses infrared temperature sensor to detect infrared energy radiated from the forehead. The intensity of the emitted energy depends on the temperature of the object. The infrared probe can recognize the emitted energy and transfer it to an electronic signal. The electronic signal can be processed in the Infrared Thermometer to convert to a temperature reading, which is displayed on the screen. This is a continuous non-invasive method of measuring body temperature. After measuring the forehead temperature with an infrared temperature sensor, the calculated temperature value is obtained. The device is not sterile and the transducers are reusable and do not need sterilization and re-sterilization. The device is for over-the-counter use.
The Infrared Thermometer, Model CFT-308, consists of the following parts:
a) Infrared sensor
b) Integrated circuit
c) Microprocessor (with Bluetooth function) (Bluetooth transmission is optional)
d) OLED display
e) Buzzer
f) 2 Buttons ("Start" button, "Measuring" button)
g) Alkaline batteries; size AAA, 2 x 1.5 V
h) Lens
Here's an analysis of the provided text regarding the acceptance criteria and study for the Infrared Thermometer (K211752):
Note: The provided document is a 510(k) summary, which often provides a high-level overview rather than granular detail for all study aspects. Some specific information (like the exact number and qualifications of experts for ground truth establishment within the clinical study, or specific effect sizes for MRMC studies if applicable) are not explicitly stated in this type of submission.
Acceptance Criteria and Reported Device Performance
The clinical study for the Infrared Thermometer Model CFT-308 aimed to demonstrate accuracy compared to a reference thermometer. The accuracy criteria are derived from the referenced standards, specifically ISO 80601-2-56:2017 and ASTM E1965-98:2016.
| Acceptance Criteria (from referenced standards) | Reported Device Performance (from "Accuracy" row in Table II-1 and clinical study) |
|---|---|
| ISO 80601-2-56:2017 & ASTM E1965-98:2016 Accuracy Requirements: | |
| Laboratory Accuracy: | |
| ±0.2°C (for 35.0°C ~ 42.0°C) | ±0.2°C: 35.0 ~ 42.0°C |
| ±0.3°C (for 32.0-34.9°C and 42.1-43.0°C) | ±0.3°C: 32.0~34.9°C, ±0.3°C: 42.1 ~ 43.0°C |
| ±0.4°F (for 95°F~107.6°F) | ±0.4°F for 95°F~107.6°F |
| ±0.5°F (for ranges outside 95°F~107.6°F) | Outside that range ±0.5°F |
| Clinical Accuracy: (Demonstrated through comparison with a reference thermometer, ensuring the subject device meets its declared accuracy range) | The clinical study results showed that the measured temperature of the subject device (CFT-308) met its declared accuracy range when compared to the reference armpit thermometer. |
Important Note on "Reported Device Performance": The table above directly extracts the claimed accuracy from the comparison table (Table II-1) within the 510(k) summary, which represents the device's declared accuracy. The clinical study was performed to validate this declared accuracy. The document states, "Through clinical trials, the measured temperature of subject device and armpit thermometers are compared to demonstrate the measurement accuracy of subject device meets its declared accuracy range."
Study Details
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Sample Size used for the test set and the data provenance:
- Sample Size: 150 subjects completed the clinical trial.
- 15 subjects aged 0 to 3 months.
- 35 subjects aged 3 months to 1-year-old.
- 50 subjects aged from 1 to 5 years old.
- 50 subjects aged 5 years and above.
- Data Provenance: Prospective clinical study conducted in China ("second hospital of Tianjin medical university").
- Sample Size: 150 subjects completed the clinical trial.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- The document implies that the ground truth was established by a "reference thermometer (Model Number: CRW-23)" which measured "armpit test temperature." It does not explicitly state that human experts were used to establish this ground truth beyond operating the reference thermometer. For an infrared thermometer, the reference standard is typically another calibrated thermometer (often an invasive one like an oral or rectal thermometer in some studies, or an axillary/armpit thermometer as used here) rather than expert consensus on a subjective measure. Therefore, "experts" in the traditional sense for ground truth labeling (e.g., radiologists interpreting images) are not directly applicable or specified for this type of device. The accuracy of the reference thermometer itself would be implicitly relied upon.
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Adjudication method for the test set:
- This is not applicable or specified for this type of device where the ground truth is established by a reference thermometer, not by subjective human interpretation requiring consensus.
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If a multi-reader multi-case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance:
- No, an MRMC study was not done. This device is an infrared thermometer, not an AI-assisted diagnostic tool interpreted by human readers.
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If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- Yes, for clinical accuracy, the study evaluates the performance of the device (CFT-308) itself in measuring temperature compared to a reference standard (CRW-23). While a human operates the device, the performance being assessed is the device's ability to accurately measure temperature relative to the ground truth, effectively a standalone performance assessment of the measurement component.
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The type of ground truth used:
- The ground truth was established using a reference thermometer (Model Number: CRW-23) measuring armpit temperature. This represents a form of empirical measurement/reference standard, aiming to provide an accurate physiological temperature reading against which the non-contact forehead thermometer's readings are compared.
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The sample size for the training set:
- The document does not specify a separate "training set" sample size. The clinical study described is for validation/testing. Infrared thermometers are typically calibrated during manufacturing, and their algorithms are based on physics and laboratory calibration rather than a machine learning "training set" in the common sense for AI algorithms.
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How the ground truth for the training set was established:
- As no explicit "training set" for an AI algorithm is mentioned, this question is not directly applicable. The device's underlying physics and pre-determined calibration (which leverages established temperature standards) would form its operational basis.
§ 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.