(60 days)
The 2 mHz and/ or 3 mHz obstetrical probes are indicated for the detection of fetal life from early gestation thru delivery and as a general indication of fetal well being. They can also be used to verify fetal heart viability following patient trauma.
The 4 mHz and/ or 8 mHz vascular probes are indicated for the detection of blood flow in veins and arteries for assisting in the detection of peripheral vascular disease.
The Sonotrax series of pocket dopplers are to be used by health care professionals including registered nurses, practical nurses, midwives, ultrasound technicians, and physicians assistants, by prescription from licensed physicians in hospitals, clinics and private offices.
The Sonotrax fetal Dopplers enumerated in their various models in 2. above use the tried and true principle of Dopplershift of an ultrasound signal to detect the fetal heartbeat using the 2 mHz and pr 3 mHz probes and for blood flow detection in veins and artefies using the 4 mHz and 8 mHz probes.
The Sonotrax Fetal Dopplers uses a split D piezoelectric transducer. A high frequency oscillator supplies a continuous high frequency voltage to one half of the split D transmitter transducer. The high frequency voltage is converted to an ultrasound acoustic wave by the transducer and is transmitted to biophysical objects thru an applied coupling water based medium and moves thru biophysical objects. The acoustic ultrasound is reflected by moving blood cells and moving objects such as the fetal heart. The reflected ultrasound is received by the second split D receiver transducer and is converted via the piezoelectric effect into a high frequency electronic signal. The received electronic signal is amplified and detected. The result is a base band audio Doppler shifted signal which is filtered , and converted to audio via a loud speaker. At the same time the fetal heart rate is applied to and displayed on a liquid crystal counter display.
The Sonotrax product includes four interchangeable probes (2mHz and 3 mHz Obstetrical probes and 4mHz and 8mHz vascular probes).
The user interface includes an on/off button, a play /record button (only in the Sonotrax Pro model), a loud speaker, headphone jack, LCD display for heartrate (all models except Sonotrax lite), and a battery.
The provided 510(k) submission for the Sonotrax Ultrasonic Fetal and Vascular Pocket Doppler (K080087) does not contain acceptance criteria or a specific study that proves the device meets such criteria in terms of a quantifiable performance metric (e.g., sensitivity, specificity, accuracy).
Instead, the submission focuses on demonstrating substantial equivalence to predicate devices. This means the manufacturer is asserting the new device is as safe and effective as devices already legally marketed, rather than providing novel performance data for specific clinical metrics.
Here's a breakdown of the information given, highlighting why certain requested details are absent:
- Table of Acceptance Criteria and Reported Device Performance: This information is not explicitly provided in the submission. The submission states "various performance tests designed to ensure that the device meets all of its functional requirements and performance specifications" were conducted (Page 3, Section 9), but these specific criteria and their results are not detailed.
- Sample Size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective): No specific "test set" and associated sample size are mentioned for a clinical performance study. The submission describes a design control process with "extensive safety, performance testing and validations" on Page 3, Section 9, but these are likely engineering and functional tests, not clinical performance studies on patient data.
- Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience): Since no clinical performance study with a test set of patient data is described, there's no mention of experts establishing ground truth for such a set.
- Adjudication method (e.g. 2+1, 3+1, none) for the test set: As no clinical test set is described, there is no adjudication method mentioned.
- 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: Not applicable. This device is a basic Doppler, not an AI-assisted diagnostic tool. No MRMC studies are mentioned or implied.
- If a standalone (i.e. algorithm only without human-in-the loop performance) was done: Not applicable. This device is a hardware instrument (Doppler) that produces an auditory and visual (heart rate display) output, requiring human interpretation. There's no "algorithm only" performance to evaluate.
- The type of ground truth used (expert consensus, pathology, outcomes data, etc): Not applicable, as no clinical performance study dependent on ground truth for diagnostic accuracy is detailed.
- The sample size for the training set: Not applicable. This device is not an AI/ML model that requires a training set of data.
- How the ground truth for the training set was established: Not applicable.
Summary of Device Acceptance and "Study" Information as Presented:
The submission explicitly states that the basis for clearance is substantial equivalence to predicate devices (K040480 Sonotrax Ultrasonic Pocket Doppler and K024197 LifeDop Doppler Ultrasound System).
The primary "proof" that the device meets acceptance criteria appears to be:
- Design Control and Testing: "The Sonotrax Ultrasonic Fetal and Vascular Doppler devices have been designed under design control procedures in the company's QSR system... and subjected to extensive safety, performance testing and validations before release. Final testing... includes various performance tests designed to ensure that the device meets all of its functional requirements and performance specifications. Safety tests have further been performed to ensure the device complies with applicable industry and safety standards." (Page 3, Section 9)
- Literature Review: "A review of the literature pertaining to the safety of Doppler Blood flowmeters has been conducted and appropriate safeguards have been incorporated in the design..." (Page 3, Section 10)
- Conclusion of Equivalence: "The conclusion drawn from these tests is that the Sonotrax Ultrasonic Fetal and Vascular Dopplers described herein are equivalent in safety and efficacy to the predicate devices." (Page 3, Section 10)
This submission relies on engineering verification and validation (V&V) against internal specifications and compliance with safety standards, rather than a clinical trial demonstrating specific performance metrics. The FDA's clearance letter (Page 4) confirms the finding of "substantial equivalence" based on this documentation.
§ 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).