(337 days)
The SD3 Series Ultrasonic Pocket Dopplers (hereinafter called "the Doppler") are intended to be used by health care professionals including registered nurses, midwives, ultrasound technicians, and physician assistants, by prescription from licensed physicians in hospitals, clinics and private offices.
The 2 MHz and/or 3 MHz waterproof probes are indicated for the detection of fetal heart rate from early gestation thru delivery and as a general indication of fetal well being. The 3 MHz waterproof probe is used for more than 9-week gestation and the 2 MHz is used for 12-week gestation. They can also be used to verify fetal heart viability.
The 4 MHz, 5 MHz and/or 8 MHz waterproof vascular probes are indicated for the detection of blood flow in veins and arteries for assisting in the detection of peripheral vascular disease.
The SD3 series Ultrasonic Pocket Doppler is a hand-held device for non-invasive measurement and display of fetal heart rate and blood flow velocity utilizing the principle of Doppler shift of an ultrasound. The ultrasound is transmitted from the probe to patient body (maternal abdominal wall), and moves through biophysical objects. The acoustic ultrasound is reflected by blood and moving objects such as the fetal heart. The reflected ultrasound is received by the probe and is converted into electric signals. The waveform data are applied to the CPU for all the digital processing on OLED Display, operation keys. The audio signal is taken off for the routing to the speaker to generate the analogue signals before digital processing. The following probes are supplied with the SD3 series Ultrasonic Pocket Doppler: 1. 2 MHz for fetal heart rate. 2. 3 MHz for fetal heart rate 3. 4 MHz for detections of arterial and venous blood flow velocity. 4. 5 MHz for detections of arterial and venous blood flow velocity. 5. 8 MHz for detections of arterial and venous blood flow velocity.
The provided document describes the Edan Instruments, Inc. SD3 Series Ultrasonic Pocket Doppler (K140579). Here's an analysis of the acceptance criteria and supporting studies:
1. Table of Acceptance Criteria and Reported Device Performance
| Feature/Test | Acceptance Criteria | Reported Device Performance |
|---|---|---|
| FHR Measuring Range | 50 bpm ~ 240 bpm | 50 bpm ~ 240 bpm (Met) |
| FHR Resolution | 1 bpm | 1 bpm (Met) |
| FHR Accuracy | ±2 bpm (for 2MHz and 3Mhz probes) | ±2 bpm (Met, based on FHR simulator testing) |
| FHR Sensitivity (3 MHz probe) | 9 weeks gestation | 9 weeks gestation (Met, based on clinical testing) |
| FHR Sensitivity (2 MHz probe) | 12 weeks gestation | 11-week to 13-week gestation (Met, based on clinical testing) |
| Clinical Detection Rate (2 MHz, 11-13 weeks) | 95% "pass" rate | 157 out of 162 cases (96.9%) were "pass" (Met) |
| Clinical Detection Rate (3 MHz, 9-10(+) weeks) | 95% "pass" rate | 95 out of 99 cases (95.9%) were "pass" (Met) |
| Repeatability of FHR measurements | 95% confidence | Repeatable to a 95% confidence (Met, based on Students T-test) |
2. Sample Sizes Used for the Test Set and Data Provenance
- FHR Accuracy and Repeatability: The document doesn't specify a sample size for the FHR simulator testing (non-clinical). It only states that a simulator was used.
- Clinical Detection Rate:
- 2 MHz probe: 162 tests for 11-week to 13-week pregnant women.
- 3 MHz probe: 99 tests for 9-week to 10(+)-week pregnant women.
- Data Provenance: The document does not explicitly state the country of origin for the clinical data. It mentions "Physicians at 6 hospitals," but the location of these hospitals is not specified. However, the submitter Edan Instruments, Inc. is based in Shenzhen, P.R. China, suggesting the data may be from China, but this is not confirmed. The studies are prospective in nature, as they involve actively taking measurements.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
- FHR Accuracy and Repeatability (Non-clinical): For the FHR simulator testing, the "ground truth" was established by the FHR simulator itself, which provides a known, controlled FHR. No human experts were involved in establishing this ground truth.
- Clinical Detection Rate: The "ground truth" for the clinical tests was likely the presence of a fetal heart rate (FHR) that could be detected. The determination of a "pass" or "fail" (whether FHR could be detected by the device) was made by "physicians at 6 hospitals." Their specific qualifications beyond "physicians" are not detailed, but the intended users are described as "health care professionals including registered nurses, practical nurses, midwives, ultrasound technicians, and physician assistants, by prescription from licensed physicians." It's implied that these professionals are the ones making the assessment during the clinical tests.
4. Adjudication Method for the Test Set
The document does not describe an explicit adjudication method (like 2+1 or 3+1 consensus) for the clinical tests. The "pass" or "fail" determination for FHR detection appears to be a direct result of whether the device could detect an FHR and was likely determined by the operating healthcare professional.
5. If a Multi Reader Multi Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size
No, a Multi Reader Multi Case (MRMC) comparative effectiveness study comparing human readers with and without AI assistance was not conducted. This device is an ultrasonic pocket doppler, not an AI-powered diagnostic tool requiring human-in-the-loop performance measurement. The evaluation focuses on the device's ability to detect FHR and blood flow.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done
Yes, a standalone performance evaluation was done for the device's core functionality.
- FHR Accuracy and Repeatability: These were tested using an FHR simulator, which is an assessment of the device's performance in a controlled environment without human interpretation influencing the measurement itself.
- Clinical Detection Rate: While humans (healthcare professionals) operated the device, the "pass" or "fail" criterion was whether the device itself could detect the FHR. This is a measure of the device's standalone capability in a clinical setting.
7. The Type of Ground Truth Used
- FHR Accuracy and Repeatability: Instrumental ground truth (established by an FHR simulator providing known values).
- Clinical Detection Rate: Clinical observation/detection by healthcare professionals, confirming the presence or absence of a detectable fetal heart rate. It's not explicitly stated if this was confirmed by another gold standard (e.g., a full ultrasound), but the primary goal was to show the Doppler's ability to detect.
8. The Sample Size for the Training Set
The document does not mention any training set. This is a typical regulatory submission for a hardware medical device with embedded algorithms, not a machine learning or AI algorithm that requires a separate training phase with a distinct training dataset. The device operates based on physics principles (Doppler shift) and signal processing, not on learned patterns from a training set in the AI sense.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as no training set for a machine learning algorithm was mentioned or used.
§ 884.2660 Fetal ultrasonic monitor and accessories.
(a)
Identification. A fetal ultrasonic monitor is a device designed to transmit and receive ultrasonic energy into and from the pregnant woman, usually by means of continuous wave (doppler) echoscopy. The device is used to represent some physiological condition or characteristic in a measured value over a period of time (e.g., perinatal monitoring during labor) or in an immediately perceptible form (e.g., use of the ultrasonic stethoscope). This generic type of device may include the following accessories: signal analysis and display equipment, electronic interfaces for other equipment, patient and equipment supports, and component parts. This generic type of device does not include devices used to image some relatively unchanging physiological structure or interpret a physiological condition, but does include devices which may be set to alarm automatically at a predetermined threshold value.(b)
Classification. Class II (performance standards).