(91 days)
The Stethee™ Pro 1 is an electronic stethoscope intended for medical diagnostic purposes only. It may be used for the detection and amplification of sounds from the heart, lungs, arteries, veins, and other internal organs. It can be used on any person undergoing a physical assessment.
The M3DICINE Stethee™ Pro 1 is an electronic stethoscope that picks up sounds of the heart, arteries, veins, lungs and other internal organs. Stethee™ Pro 1 provides capability for auscultation in frequencies from 20-2000Hz.
After amplification and filtering, the sounds are transferred to the user's ears via any Bluetooth connected headphones. The Stethee™ Pro 1 includes features that permit it to record and store sounds on a peripheral smart device (e.g., mobile phone) by transferring the sounds as an audio buffer to the smart device via a Bluetooth® connection. The smart device makes use of a downloaded companion stand-alone Mobile Medical Application (MMA), Stethee™ App, to record, manage and replay the captured patient sounds on the smart device.
Stethee™ App is also able to display the audio file as a phonocardiograph (21 CFR 870.2390) on the user's smart device and can use the audio file to calculate and display a simple Heart Rate. Stethee™ App does not direct or influence the performance of Stethee™ Pro 1.
The Stethee™ Pro 1 device user interface includes a simple push down mechanism ("control knob") to start recording. It has a light-emitting diode (LED) display ring which indicates the device's status state (ON or OFF, charge status, and Bluetooth® synchronization status).
The Stethee™ Pro 1 operates on a rechargeable certified 3.7V lithium ion polymer battery.
The Stethee™ Pro 1 incorporates embedded software. The embedded software controls all the various features found in the Stethee™ Pro 1, such as sound capture, digital signal processing, volume control, LED display ring, and Bluetooth® transfer.
The document describes the Stethee™ Pro 1 electronic stethoscope and its equivalence to a predicate device, the 3M™ Littmann® Model 3200. However, it does not provide acceptance criteria in terms of specific performance metrics with numerical targets or a detailed study proving the device meets those specific acceptance criteria.
Instead, the document focuses on demonstrating substantial equivalence to a predicate device through comparative performance testing.
Here's an attempt to answer your questions based on the provided text, highlighting what information is available and what is not:
1. Table of acceptance criteria and the reported device performance
The document does not explicitly state "acceptance criteria" in the format of defined thresholds for different performance metrics. It rather presents a comparison of technical characteristics between the Stethee™ Pro 1 and the predicate device. The implied "acceptance criteria" is that the Stethee™ Pro 1 performs substantially equivalent to the predicate device in these characteristics.
| Feature | Implied Acceptance Criteria (Substantial Equivalence to Predicate) | Stethee™ Pro 1 Reported Performance |
|---|---|---|
| Classification | Electronic Stethoscope, Class II, DQD | Electronic Stethoscope, Class II, DQD |
| Intended Use | Medical diagnostic purposes, detection/amplification of internal sounds, used on any person undergoing physical assessment | Same as predicate |
| Contraindications | None | None |
| Pickup Sensor | Convert sound waves to digital signal | Microphone (-22 dB sensitivity), Sampling Rate: 16kHz, Bit Rate: 16 bits |
| Frequency Response | Responsive in audible ranges, comparable to predicate's Bell/Diaphragm/Extended Range | Responsive from 20-2000Hz |
| Maximum Sound Level | Amplifies up to 24X | Amplifies up to 24X |
| Volume Control | Yes, in 8 steps | Yes, in 8 steps |
| Power Source | Battery-powered | Rechargeable Lithium-ion polymer battery |
| Low Battery Indicator | Yes | Yes (LED color change) |
| Operating Controls & Indicators | ON/OFF, status indication | ON/OFF features by electronics (tapping mechanism), LEDs for status (ON/OFF, charging, Bluetooth® synchronization) |
| Heart Rate: Detection & Display | Yes, displayed on device or peripheral | Yes, using companion Stethee™ App (MMA) |
| Heart Rate: Minimum Audio Sample Requirements | 5 seconds recording | 0.3-2 second recording |
| Heart Rate: Methodology | Continuous real-time calculation, updated every few seconds | Continuous real-time calculation after initial 0.3-2 second sampling, updates after each heart beat |
| Heart Rate: Range of Detection & Accuracy | 30-199 BPM with ±10% consistency or ±5 bpm | 30-200 BPM with allowable readout error rate of no greater than ±10 % (i.e., 10% consistency) of the input rate or ±5 bpm |
| Heart Rate: Handling of inconsistent sounds | Inconsistent sounds indicated by "-" | Inconsistent sounds displayed on Stethee™ App GUI as "-" |
| Direct Listening | Real-time sound listening capability | Real-time listening using a Bluetooth® enabled headset |
| Recording and Playback | Capability to record and playback sounds | With Stethee™ App (not on device itself) |
| Visualization | Sounds visualized as phonocardiograph using software | Sounds visualized as phonocardiograph using companion software Stethee™ App |
| Wireless Technology & Peripheral Platform Compatibility | Bluetooth® at 2.4 GHz, compatible with devices | Bluetooth® at 2.4 GHz, compatible with Android and iOS devices |
| Ambient & Frictional Noise Reduction Technology | Yes | Yes |
2. Sample size used for the test set and the data provenance
The document states: "M3DICINE submitted performance testing information in this 510(k) demonstrating that the Stethee™ Pro 1 can perform over its intended range of operation (20-2000Hz). Comparative performance testing submitted in the 510(k) demonstrated the two devices perform in a substantially equivalent manner."
However, no specific sample sizes for test sets or data provenance (e.g., country of origin, retrospective/prospective) are mentioned for this comparative performance testing.
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 in the document. The testing described is comparative performance testing against a predicate device, not necessarily a diagnostic study requiring expert ground truth for classification.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
This information is not provided in the document.
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
No MRMC comparative effectiveness study was described or performed. The device is an electronic stethoscope with an accompanying app that can display phonocardiographs and heart rate. It's not an AI-assisted diagnostic tool in the sense of improving human reader performance on complex image interpretation. The comparison is primarily on technical specifications and basic functionality.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done
The document describes the performance of the Stethee™ Pro 1 device itself, which includes embedded software for sound capture, digital signal processing, volume control, and Bluetooth transfer. The heart rate calculation by the Stethee™ App can be considered an "algorithm only" function in terms of its calculation process.
- Heart Rate Calculation: The Stethee™ App "calculates and display a simple Heart Rate."
- Minimum Audio Sample Requirements: Requires initial 0.3-2 second recording (predicate requires 5 seconds).
- Methodology: Performs continuous real-time calculation after initial 0.3-2 second sampling and updates heart rate display after each heart beat (predicate updates every 2 seconds after initial 5 seconds).
- Range of Detection and Accuracy: 30-200 BPM with an allowable readout error rate of no greater than ±10 % or ±5 bpm (predicate: 30-199 BPM with ±10% consistency).
- Visualization: "Sounds can be visualized as phonocardiograph using companion software Stethee™ App." This is a standalone function of the software.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
For the heart rate accuracy, the implied ground truth would be a validated heart rate measurement, likely from an ECG or a highly accurate reference device. However, the exact type of ground truth used for performance testing is not explicitly stated. For the broader "substantial equivalence" claim, the predicate device itself serves as the reference for comparison.
8. The sample size for the training set
The document does not mention a training set or any machine learning/AI model training in the context of diagnostic capabilities beyond basic heart rate calculation. The "embedded software" handles signal processing and device control but isn't described as a learnable AI model.
9. How the ground truth for the training set was established
As no training set is mentioned in the context of the device's diagnostic claims, this information is not applicable/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.