(157 days)
Infrared Thermometer (model: ZST-A) is a non-sterile, reusable, non-contact and handheld device. It can be used by consumers in homecare environment and doctors in clinic as reference. It is intended for measuring human body temperature of people over one month old by detecting infrared heat from the forehead.
The Infrared Thermometer, Model ZST-A is a non-contact long-distance infrared thermometer which is specialized in measuring human body temperature. It contains buzzer prompt, memory reading, backlight reminder, temperature offset setting, alarm threshold setting, automatic shutdown and common functions of equipment. The Infrared Thermometer measures the temperature by using the principle of receiving infrared. The product is composed of built-in infrared detector and related hardware and software, which can receive, analyze and record the measured object and ambient temperature. Therefore, once the user approaches the specific part of the human body (forehead) and presses the measurement key, the infrared sensor can be activated immediately, and the thermal energy generated by the arterial blood flow can be detected quickly through the passive infrared sensor, so as to accurately measure the body temperature of the human body. The measurement distance of the subject device is 1~5 cm from the middle of the forehead.
The provided document is a 510(k) summary for an Infrared Thermometer (Model: ZST-A). It details the device's technical specifications, intended use, and comparison to a predicate device, along with non-clinical and clinical test conclusions.
Here's an analysis of the acceptance criteria and study proving the device meets them, based on the provided text:
1. A table of acceptance criteria and the reported device performance:
The primary acceptance criteria for the infrared thermometer are related to its accuracy in measuring human body temperature. The standard referenced is ASTM E1965-98.
| Acceptance Criteria (Standard: ASTM E1965-98) | Reported Device Performance (Model: ZST-A) |
|---|---|
| Accuracy | ±0.2°C (0.4°F) within 33.0°C ~ 39.0°C (91.4°F ~ 102.2°F) |
| ±0.3°C (0.5°F) other range | |
| Measurement Range | Forehead mode: 32.0°C ~ 43.0°C (89.6 to 109.4 °F) |
| Clinical Performance | Complied with the requirement of ASTM E1965-98 (2016) |
| Measurement Distance | 1~5 cm from the middle of the forehead (demonstrated to meet clinical accuracy within this range) |
2. Sample size used for the test set and the data provenance:
- Sample Size: A minimum of 105 subjects were used for the clinical study. These subjects were divided into three age groups, with at least 35 subjects per group.
- Data Provenance: The document does not explicitly state the country of origin where the clinical study was conducted. It mentions "Shandong Zhushi Pharmaceutical Group Co., Ltd." in China as the submitter, which implies the study could have been performed in China, but this is not definitively stated for the clinical trial location. The study is described as a "clinical investigation," which generally implies prospective data collection, but the document does not explicitly specify "retrospective" or "prospective." However, clinical trials are typically prospective.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
The document does not provide details on the number or qualifications of experts used to establish the ground truth for the clinical test set. For temperature measurement, the ground truth is typically established using a reference thermometer (e.g., a rectal thermometer for core body temperature, as per ASTM standards for clinical thermometry studies) rather than expert consensus.
4. Adjudication method (e.g., 2+1, 3+1, none) for the test set:
The document does not describe any adjudication method. This is typically not relevant for a temperature measurement device where a reference standard device provides the "ground truth" rather than human interpretation.
5. 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:
This is not applicable to an infrared thermometer. An MRMC study is typically performed for AI-powered diagnostic imaging devices where human readers (e.g., radiologists) interpret images with or without AI assistance. The Infrared Thermometer is a direct measurement device and does not involve human interpretation of complex data that AI would assist with.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
The device itself, the "Infrared Thermometer," operates as a standalone device. Its performance is measured directly (algorithm only, as it's an embedded system) without continuous human interaction in the measurement process other than positioning and activating the device. The clinical study assessed the device's accuracy against a recognized standard (ASTM E1965-98), which inherently evaluates its standalone performance.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
The ground truth for the clinical study would have been established by a reference clinical thermometer (e.g., a rectal or oral thermometer depending on the specific ASTM E1965-98 protocol used), which is considered the gold standard for core body temperature measurement in such studies. The document states that the clinical study was conducted "per ASTM E1965-98." This standard details the methodology for clinical accuracy assessment for infrared thermometers, which involves comparing measurements from the test device to core body temperatures obtained from a highly accurate reference thermometer.
8. The sample size for the training set:
The document does not mention a training set or any machine learning/AI training process in the conventional sense. This device is a traditional infrared thermometer, not an AI/ML-based diagnostic tool that would typically have a separate training phase. Its operation is based on established physical principles of infrared radiation detection and calibrated algorithms, not learned patterns from a large training dataset.
9. How the ground truth for the training set was established:
As no training set is mentioned or implied for this type of device, this point is not applicable.
§ 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.