(200 days)
The 3 Channel Knee Electronic Amplified Stethoscope is intended for use by a physician as a noninvasive tool to amplify and record distinct sounds (vibrations) within the three compartments (medial, lateral, and patellar) of the knee joint.
The device is intended for use by a physician as a noninvasive tool to amplify and record distinct sounds (vibrations) within the three compartments (medial, lateral, and patellar) of the knee joint.
The 3 Channel Knee Stethoscope System consists of three transducers, or sensors, to pick up the vibrations (sound) from three locations on the knee. The transducers are plugged into an amplifier box that is connected to a standard personal computer installed with Windows 3.1, or later version. A goniometer attachment is also plugged into the amplifier box. The system generates a metronome arrow that moves on the computer monitor screen (3 seconds per flex/extend cycle). The patient watches the arrow to pace the speed and direction of knee flexion and extension, while staying "in sync" with the metronome to maintain a 3 second cycle. Motion and sound vibrations are amplified, recorded in graph form, and stored in a patient database.
Here's an analysis of the provided text regarding the acceptance criteria and study for the 3 Channel Knee Electronic Amplified Stethoscope:
Acceptance Criteria and Study Analysis
Based on the provided documentation, the "acceptance criteria" for the 3 Channel Knee Electronic Amplified Stethoscope are primarily rooted in demonstrating substantial equivalence to existing legally marketed predicate devices. The device is not making claims of diagnostic capability, but rather as an adjunct tool for amplification and recording. Therefore, the "studies" presented are historical and foundational research on the broader concept of "vibration arthrography" rather than a direct, specific study proving the performance of this specific device against defined acceptance criteria.
The submission is a 510(k) for a Class II medical device, which typically relies on demonstrating equivalence rather than extensive clinical efficacy trials.
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria Category | Specific Criteria (Implicit from 510(k)) | Reported Device Performance / Supporting Evidence |
|---|---|---|
| Intended Use | To amplify and record distinct sounds (vibrations) within the three compartments of the knee joint as a noninvasive physician's tool. | The device description explicitly states this intended use. Claims equivalence to predicate stethoscopes for amplification and recording. |
| Safety | Minimize risks to the patient. | Stated as minimal risk; not intended for diagnosis, but as an adjunct. No energy applied to the patient. |
| Functionality | Magnify vibrations (sounds) and make them more discernible. Process, store, and display sound recordings. | Stated as equivalent to 3M Littmann Electronic Stethoscope for amplification and filtering. Equivalent to Transmedica Model 100 Digital Electronic Stethoscope for processing, storing, and displaying sound recordings using multiple piezoelectric transducers and a general purpose digital computer. |
| Technological Characteristics | Use of transducers, amplifier, computer interface, goniometer, metronome for pacing. | Device description details these components and their function. |
| Substantial Equivalence | Equivalent in intended use and technological characteristics to legally marketed predicate devices (3M Littmann Electronic Stethoscope, Transmedica Model 100 Digital Electronic Stethoscope). | explicitly affirmed by the FDA in the approval letter (K991756) based on the submitted information. The document extensively compares its functions to these predicates. |
| Diagnostic Claims | No interpretive or diagnostic capabilities claimed. | Explicitly stated: "There are no interpretive or other diagnostic capabilities currently claimed for this device." |
2. Sample Size Used for the Test Set and the Data Provenance
The 510(k) submission does not mention a specific test set or sample size used for the performance evaluation of this particular device. The "studies" cited are published papers on the general concept of "vibration arthrography" or electro-acoustical techniques for detecting knee joint noise, dating from 1976 to 1990. These papers are foundational for the field, but not direct performance studies of the Biomet 3 Channel Knee Electronic Amplified Stethoscope itself. Therefore, details like data provenance specific to this device's testing are not provided.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and the Qualifications of Those Experts
This information is not provided as there is no specific test set described for this device's performance evaluation. The cited published papers (e.g., Chu et al., Kernohan et al., McCoy et al., Mollan et al., Wallace et al.) in the "Published Papers" section would have involved experts in their respective studies, but these are not studies of this specific device's performance or a means to establish "ground truth" for its acceptance.
4. Adjudication Method for the Test Set
This information is not provided as there is no specific test set described for this device's performance evaluation.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, an MRMC comparative effectiveness study was not done for this device as described in the provided text. The device is not claiming interpretative or diagnostic capabilities, and the focus of the 510(k) is on substantial equivalence for amplification and recording. There is no mention of human readers improving with or without AI assistance, as the device itself is a purely signal amplification and recording tool, not an AI-driven diagnostic system.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
The concept of a "standalone" algorithm performance study is not applicable to this device in the way it's usually understood for AI/diagnostic algorithms. The device's primary function is to amplify and record, then display the data for a physician to interpret. It's a "human-in-the-loop" device by its very nature, where the human physician provides the interpretation. There is no algorithm that provides a standalone diagnostic output.
7. The Type of Ground Truth Used
Given the nature of the device (amplification and recording, not diagnosis), the concept of "ground truth" for its performance evaluation is not directly applicable in the sense of pathology, expert consensus on a diagnosis, or outcomes data. The "ground truth" for the device's acceptance is its ability to accurately amplify and record sounds and its substantial equivalence to predicate devices that perform similar functions. The historical research cited (e.g., "The Diagnosis Potential of Vibration Arthography," "Vibration Arthrography as a Diagnostic Aid") suggests that the field uses clinical findings, imaging, or surgical outcomes to correlate with vibration patterns, but this is for interpreting the data from such devices, not for validating the device's basic function of amplification and recording.
8. The Sample Size for the Training Set
This device does not contain a machine learning or AI algorithm in the contemporary sense that would require a "training set." Therefore, this information is not applicable and not provided.
9. How the Ground Truth for the Training Set Was Established
As there is no training set for an AI algorithm, this information is not applicable and not provided.
§ 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.