(511 days)
Detection and analysis of vascular disease in peripheral vessels. Evaluation of degree and site of a stenosis. Detection of occlusions and flow disturbances. Determination of vessel type and location. Measurement of relative flow velocity. Not intended for fetal use.
Stenodoc is a mains independent portable continuous wave Doppler ultrasound device with two pen-shaped split-D transducers operating at 4 MHz and 8 MHz. A 512 point fast Fourier transform (FFT) is performed on the returned signal. The spectral distribution of blood flow is represented as a frequency over time diagram with intensities represented by different shades of gray. The diagram is displayed on a liquid crystal display (LCD). Measurements can be annotated with the patient's name, vessel name and a diagnosis and can be stored on a built-in harddisk for later evaluation. Size: 3" x 13.5" x 10" (Height/Width/Depth) Weight: 9 lbs.
Please note: The provided text is a 510(k) summary for a medical device (Stenodoc Bidirectional Vascular Doppler with Spectral Analysis) from 1995. Medical device regulation and the types of studies required for market clearance have evolved significantly since then. The information available in this summary is consistent with the regulatory landscape of its time, which did not typically include the detailed statistical performance metrics, extensive clinical trial data, or specific ground truth methodologies that are common in modern AI/ML device submissions.
Based on the provided text, here is an analysis of the acceptance criteria and study information:
1. Table of Acceptance Criteria and Reported Device Performance
The provided 510(k) summary does not explicitly state "acceptance criteria" in the modern sense of quantifiable performance targets for a clinical study (e.g., sensitivity, specificity, AUC thresholds). Instead, the "acceptance criteria" are implied by the demonstration of substantial equivalence to a predicate device. The performance is assessed by comparing technical characteristics to the predicate.
| Characteristic | Acceptance Criteria (Predicate Device Value) | Reported Device Performance (STENODOC™ Value) |
|---|---|---|
| Device Type | Bidirectional Doppler | Bidirectional Doppler |
| Ultrasound mode | continuous wave | continuous wave |
| Transducers | 4 and 8MHz split D | 4 and 8MHz split D |
| ISPTA 8 MHz Probe | 90 mW/cm2 | < 94 mW/cm2 |
| ISPTA 4 MHz Probe | 69 mW/cm2 | < 80 mW/cm2 |
| Maximum Doppler frequency detection | 35 kHz | 32 kHz |
| AD-Converter | 8 bit | 12 bit |
| Spectral Analysis | 256 pt. FFT overall | 512 pt. FFT/direction |
| FFT calculation every | 6.5 ms | 10 ms |
| Physical Device Type | Desktop-Computer Style | Laptop-Computer style |
| Display | 9" diagonal tube | 9.5" diagonal LCD |
| Calculations | Maximum, Mode and Meanfrequency, Spectral broadening | Maximum, Mode and Meanfrequency, spectral broaden-ing, pulsatility and resistanceindex |
Interpretation: The "acceptance" is that the new device's characteristics are either equivalent or have technological differences that do not raise new questions of safety or effectiveness when compared to the predicate. For example, some values are slightly different (e.g., ISPTA, max frequency detection, FFT calculation speed), and some are enhanced (e.g., AD-Converter resolution, additional calculations). These differences would have been reviewed by the FDA to ensure they did not negatively impact performance as defined by the predicate.
2. Sample size used for the test set and the data provenance
The document does not explicitly describe a "test set" or any clinical study with a specific sample size for evaluating performance in the way modern AI/ML devices do. The primary mechanism for clearance is demonstrating substantial equivalence based on technological characteristics and intended use to a predicate device.
The provenance of data (e.g., country of origin, retrospective/prospective) is not mentioned because a clinical data-based performance study is not detailed.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
This information is not applicable to this 510(k) submission. A formal "ground truth" establishment by experts for a specific test set, as is common in AI/ML validation, is not described or required based on the provided text for this device's 1995 submission. The "ground truth" for showing effectiveness relies on the established effectiveness of the predicate device.
4. Adjudication method for the test set
This information is not applicable. Since no specific "test set" and expert ground truth establishment are described, there is no adjudication method detailed.
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, a multi-reader multi-case (MRMC) comparative effectiveness study was not done, and therefore no effect size regarding human reader improvement with AI assistance is reported. This device is a diagnostic ultrasound system (Doppler with spectral analysis), not an AI-powered diagnostic aid in the modern sense. Its function is to provide physiological measurements (blood flow velocity and characteristics) for clinicians to interpret.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done
The concept of a "standalone" algorithmic performance, as understood for AI/ML devices, is not applicable here. The device itself (Stenodoc) performs the spectral analysis (FFT) and calculations. Its performance is inherent to its technical specifications and comparison to the predicate, rather than being an algorithm that makes a diagnostic "call" independent of a human. The device generates data (spectral traces, calculated indices) that a clinician then interprets.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
The document does not specify an explicit type of "ground truth" used for clinical performance evaluation. For a 510(k) submission, the "ground truth" for the device's functionality and effectiveness is implicitly established by the predicate device's known performance and intended use. The new device is deemed safe and effective because its technological characteristics are substantially equivalent to a device already on the market with a history of safe and effective use.
8. The sample size for the training set
This information is not applicable. The device is not an AI/ML algorithm that is "trained" on a dataset in the modern sense.
9. How the ground truth for the training set was established
This information is not applicable, as there is no "training set" for an AI/ML algorithm involved in this 1995 device submission.
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Summary of Safety and Effectiveness
510(k) Diagnostic Ultrasound Devices
This summary of 510(k) safety and effectiveness information is being submitted in accordance with the requirements of 21 CFR 807.92 and was prepared April 27, 1995.
| Submitter: | SPECS USA, Inc.Suite 3122. North Tamiami TrailSarasota, FL 34236Phone: (813) 362-4877MAY 24 1996 |
|---|---|
| Contact Person: | Dr. Ulrich R. Herken, Manager R&D |
| Common Name: | Bidirectional Vascular Doppler with Spectral Analysis. |
| Proprietary Name: | Stenodoc |
| Classification Name: | Nonfetal ultrasonic monitor, 21 CFR 892.1540. |
| Classification: | Classification of this ultrasonic device under Section 513 of theact is Class II. |
| Predicate Device: | The Stenodoc Bidirectional Vascular Doppler with SpectralAnalysis is substantially equivalent to the Multigon 500A Vas-cular Spectrum Analyzer with Doppler, Reference K850435,which was declared substantially equivalent to predicate devicesMay 5, 1986. |
| Description: | Stenodoc is a mains independent portable continuous waveDoppler ultrasound device with two pen-shaped split-D trans-ducers operating at 4 MHz and 8 MHz. A 512 point fast Fouriertransform (FFT) is performed on the returned signal. The spec-tral distribution of blood flow is represented as a frequency overtime diagram with intensities represented by different shades ofgray. The diagram is displayed on a liquid crystal display(LCD). Measurements can be annotated with the patient's name,vessel name and a diagnosis and can be stored on a built-in hard-disk for later evaluation.Size: 3" x 13.5" x 10" (Height/Width/Depth) Weight: 9 lbs. |
| Intended use: | Detection and analysis of vascular disease in peripheral vessels.Evaluation of degree and site of a stenosis. Detection of occlu-sions and flow disturbances. Determination of vessel type andlocation. Measurement of relative flow velocity. Not intendedfor fetal use. |
VII
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510(k) Diagnostic Ultrasound Devices
| Characteristic | STENODOC™ | Multigon 500A |
|---|---|---|
| Device Type | Bidirectional Doppler | Bidirectional Doppler |
| Ultrasound mode | continuous wave | continuous wave |
| Transducers | 4 and 8MHz split D | 4 and 8MHz split D |
| ISPTA 8 MHz Probe | < 94 mW/cm2 | 90 mW/cm2 |
| ISPTA 4 MHz Probe | < 80 mW/cm2 | 69 mW/cm2 |
| Maximum Doppler fre-quency detection | 32 kHz | 35 kHz |
| AD-Converter | 12 bit | 8 bit |
| Spectral Analysis | 512 pt. FFT/direction | 256 pt. FFT overall |
| FFT calculation every | 10 ms | 6.5 ms |
| Physical Device Type | Laptop-Computer style | Desktop-Computer Style |
| Display | 9.5" diagonal LCD | 9" diagonal tube |
| Calculations | Maximum, Mode and Meanfrequency, spectral broaden-ing, pulsatility and resistanceindex | Maximum, Mode and Meanfrequency, Spectral broadening |
Summary of technological characteristics of Stenodoc and the predicate device.
viii
§ 892.1560 Ultrasonic pulsed echo imaging system.
(a)
Identification. An ultrasonic pulsed echo imaging system is a device intended to project a pulsed sound beam into body tissue to determine the depth or location of the tissue interfaces and to measure the duration of an acoustic pulse from the transmitter to the tissue interface and back to the receiver. This generic type of device may include signal analysis and display equipment, patient and equipment supports, component parts, and accessories.(b)
Classification. Class II (special controls). A biopsy needle guide kit intended for use with an ultrasonic pulsed echo imaging system only is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 892.9.