(112 days)
The Withings Thermo (Model SCT01) is a non-sterile, reusable clinical thermometer intended for the intermittent determination of human body temperature in a touch mode over the measurement site on people of all ages.
The Withings Thermo (Model SCT01) is a hand-held, battery powered device designed to measure human body temperature. The SCT01 device is an infrared thermometer that, when placed in contact with the user's skin over the temporal artery, measures the natural infrared energy emitted from the surface of the skin and convert it to an oral equivalent temperature.
The Withings Thermo (Model SCT01) thermometer uses a thermopile sensor for the target reading, a thermistor-like pin junction for ambient temperature readings, and a silicon lens to focus the radiated energy on the thermopile sensor. It embeds a 20x5 LEDs matrix for display of results, and also a Wi-Fi/ Bluetooth module for optional usage of a smartphone application to log results
Here's an analysis of the acceptance criteria and study proving the device meets them, based on the provided text:
Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (from Predicate Device/Standard) | Reported Device Performance (Withings Thermo SCT01) |
|---|---|
| Clinical Accuracy: ± 0.2°C (35.5°C – 42.0°C range) / ± 0.4°F (95.9°F – 107.6°F range) | The clinical testing indicated that "the deviation of temperature measurement deviation between Withings SCT01 and Braun NTF3000US is within acceptable range of the performance requirement of ISO 80601-2-56." This implies the device meets the stated accuracy of ± 0.2°C / ± 0.4°F. |
| Clinical Accuracy: ± 0.3°C / ± 0.5°F outside the 35.5°C – 42.0°C range | Implied to be met, as the overall deviation was within acceptable range per ISO 80601-2-56. |
Study Details:
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Sample size used for the test set and the data provenance:
- The document states that clinical testing was conducted "according to the requirement set out on ASTM 1965: 2009 standard." However, it does not explicitly mention the sample size (number of participants) used in this clinical test.
- Data Provenance: Not explicitly stated (e.g., country of origin, retrospective or prospective). However, clinical testing implies prospective data collection for the purpose of validating the device.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not specified. The ground truth in this context would typically be a highly accurate reference thermometer measurement. The document doesn't detail how this reference was established or if human experts were involved in defining the "ground truth" for temperature readings as opposed to simply performing the reference measurements.
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Adjudication method (e.g. 2+1, 3+1, none) for the test set:
- Not applicable/Not specified. For a temperature measurement device, adjudication methods like 2+1 are typically used for subjective diagnoses or interpretations (e.g., radiology). For a quantitative measurement like temperature, the ground truth is typically a direct measurement from a highly calibrated and accurate reference device, not an expert consensus process.
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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 type of study is relevant for devices that assist human interpretation (e.g., AI in medical imaging). The Withings Thermo is a standalone measurement device, not an AI-assisted diagnostic tool that requires human interpretation.
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If a standalone (i.e. algorithm only without human-in-the loop performance) was done:
- Yes, a standalone performance study was done. The clinical testing evaluated the "accuracy of body temperature measurement between Withings Thermo (Model SCT01) and Braun NTF3000US." This is a direct comparison of the device's output against a predicate device, which itself is a standalone measurement tool. The device is designed for standalone use for temperature measurement.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc):
- The ground truth for temperature measurement would be measurements from a highly accurate and calibrated reference thermometer, conforming to established standards (e.g., ASTM 1965: 2009). The document compares the SCT01's readings to those of the Braun NTF3000US, which is presumably used as a proxy for, or in direct comparison to, such a reference.
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The sample size for the training set:
- Not specified. The document does not provide details about a training set. Infrared thermometers often use predictive algorithms, but the text focuses on clinical validation, not the development or training of such algorithms. It mentions "predictive algorithms to estimate the body temperature" for both the subject and predicate devices, implying these are established and refined during product development, but specific training set sizes are not disclosed for regulatory submission.
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How the ground truth for the training set was established:
- Not specified, as training set details are not provided. If a training set were used to refine predictive algorithms, its ground truth would typically be established through highly precise measurements using reference standards in controlled environments, often including invasive core body temperature measurements for correlation. The document does not elaborate on this aspect.
§ 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.