(164 days)
The intended use of American Telecare, Inc.'s CareTone II is to conduct a stethoscope examination of a patient by a nurse or physician at another location using a communications line.
To use the CareTone, a patient plugs the sending unit's telephone cable into a telephone wall outlet and the examiner plugs the receiving unit's telephone cable into a telephone wall outlet. The examiner dials the patient's telephone number to connect the receiving unit and sending unit over the telephone line. When the connection is made, the patient places the stethoscope chest piece on his/her chest. The sounds captured by the chest piece are transmitted to the patient end unit of the sending unit by a microphone located within the chest piece. The signal is processed within the circuitry of the patient end unit and transmitted over the telephone line to the receiving unit and through headphones to the examiner.
The provided 510(k) summary for the American Telecare, Inc.'s CareTone II Telephonic Stethoscope is a submission seeking substantial equivalence to a predicate device, the CareTone Telephonic Stethoscope. This type of submission focuses on demonstrating that the new device is as safe and effective as a legally marketed predicate device, rather than providing extensive clinical study data for novel acceptance criteria.
Based on the provided text, the "acceptance criteria" discussed are primarily related to the equivalence in performance and safety to the predicate device rather than rigorously quantified clinical performance targets. The "study" proving this largely relies on engineering tests and a qualitative physician assessment.
Here's an attempt to answer your request based only on the provided text:
1. A table of acceptance criteria and the reported device performance
| Acceptance Criteria (Inferred from Substantial Equivalence Claim) | Reported Device Performance and Evidence (from text) |
|---|---|
| Safety: Device operates without introducing new safety concerns compared to predicate. | EMC/EMI testing: "The safety and effectiveness of the modified device, the CareTone II, has been demonstrated by EMC/EMI testing..." |
| Effectiveness/Signal Quality: Transmitted auscultatory signal quality is comparable/acceptable for diagnostic use by a physician. | Physician Assessment: "...and a physician assessment of the quality of the signal received." |
The text emphasizes: "It also has very similar principles of operation and technological characteristics as they both transmit an auscultatory signal to a receiver. The minor technological differences between the CareTone II and the CareTone, primarily, use of companding circuitry and the use of data communication cables, do not raise new questions of safety or effectiveness." This implies the "acceptance" is that these changes do not degrade effectiveness. |
| Intended Use: Device maintains the same intended use as the predicate. | Same Intended Use: "The CareTone II has the same intended use as the CareTone: to conduct a stethoscope examination of a patient by a nurse or physician at another location using a communications line." |
| Principles of Operation & Technological Characteristics: Similar to predicate. | Similarities stated: "It also has very similar principles of operation and technological characteristics as they both transmit an auscultatory signal to a receiver." |
2. Sample size used for the test set and the data provenance
The document does not specify a quantitative sample size for any clinical test set. The "physician assessment" is mentioned, but details on the number of patients, recordings, or the nature of the assessment (e.g., specific clinical scenarios) are absent. Data provenance is not specified (e.g., country of origin) and the assessment appears to be prospective in nature as it evaluates the new device specifically.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
The document mentions "a physician assessment." It does not specify the number of physicians involved, nor does it detail their qualifications (e.g., "radiologist with 10 years of experience").
4. Adjudication method for the test set
The document does not describe any formal adjudication method (e.g., 2+1, 3+1). The assessment is simply referred to as "a physician assessment."
5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done
No MRMC comparative effectiveness study is described. The assessment is qualitative and focuses on the signal quality of the CareTone II itself, rather than a comparative study of human readers with and without AI assistance. (Note: This device is a telephonic stethoscope, not an AI diagnostic tool, so an MRMC study in the context of AI assistance would not be expected.)
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
The CareTone II is a medical device for transmitting sounds, not an algorithm. Therefore, "standalone algorithm-only performance" is not applicable in the way it would be for an AI diagnostic tool. Its performance is intrinsically tied to human interpretation of the transmitted sounds. The "physician assessment" mentioned is effectively the human-in-the-loop performance.
7. The type of ground truth used
The concept of a formal "ground truth" (e.g., pathology, outcomes data) in the context of a diagnostic aid like a telephonic stethoscope is less straightforward than for a disease detection AI. For this device, the "ground truth" for its effectiveness is implicitly assumed to be the clinical interpretability and utility of the sounds transmitted by the device, as judged by a physician. The document states "a physician assessment of the quality of the signal received," which serves as the surrogate for "ground truth" in this context.
8. The sample size for the training set
This document describes a 510(k) submission for a physical medical device (telephonic stethoscope), not an AI algorithm. Therefore, there is no "training set" in the machine learning sense. The device is built based on established engineering principles and, in this case, by modifying an existing predicate device.
9. How the ground truth for the training set was established
As there is no "training set" in the AI sense, this question is not applicable. The functional performance of the device (signal transmission) is verified through engineering tests and the qualitative physician assessment.
§ 870.1875 Stethoscope.
(a)
Manual stethoscope —(1)Identification. A manual stethoscope is a mechanical device used to project the sounds associated with the heart, arteries, and veins and other internal organs.(2)
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 § 870.9.(b)
Electronic stethoscope —(1)Identification. An electronic stethoscope is an electrically amplified device used to project the sounds associated with the heart, arteries, and veins and other internal organs.(2)
Classification. Class II (special controls). The device, when it is a lung sound monitor, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 870.9.