(455 days)
PUREtrace™ is an electromyography (EMG) device that non-invasively measures intrapartum uterine activity. PUREtrace™ is indicated for use on women who are at term (≥37 completed weeks), in labor, with singleton pregnancies. The signal is acquired from surface electrodes that are placed on the maternal abdomen. PUREtrace™ is intended for use by healthcare professionals in a clinical setting.
PUREtrace is a device for registering the electrical activity of the uterine muscle (myometrium) of laboring patients. PUREtrace consists of a multi surface-electrode patch (Graphium patch) and a hardware module (PUREtrace module). The Graphium patch is applied to the abdomen of the patient and acquires the electromyography (EMG) signal of the uterine muscle (electrohysterography, EHG). During a contraction, a large number of uterine muscle cells contract in a controlled manner and the changes in potential can be measured as changes in electrical on the skin of the pregnant woman's abdomen. This signal is sent to the PUREtrace module, converted into a measure for uterine activity and subsequently sent to a compatible fetal monitor where it is displayed as a tocogram. PUREtrace is available in multiple variants with different output connectors to facilitate interfacing with various fetal monitors.
Here's a summary of the acceptance criteria and the study conducted for the PUREtrace™ device, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The provided 510(k) summary does not explicitly state numerical acceptance criteria in a table format. However, it implicitly uses the concept of "substantial equivalence" to a predicate device as the primary acceptance criterion. The performance is reported in terms of the device's ability to display uterine activity comparably to existing methods.
| Acceptance Criterion (Implicit) | Reported Device Performance |
|---|---|
| Safety and Effectiveness: Complies with relevant standards | Non-clinical tests demonstrated compliance with ISO 10993-1:2009 (biocompatibility), IEC 60601-1:2005 (electrical safety), and IEC 60601-1-2:2007 (EMC). Software V&V also conducted. |
| Clinical Performance: Substantially equivalent to predicate | Clinical study demonstrated that PUREtrace™ performed substantially equivalent to the predicate device (Monica AN24) for displaying uterine activity of term pregnant women in active labor. |
| Interpretability of Tracings: (Implicit) | Clinical investigators assessed the interpretability of the tracings, and annotated deflections they assessed to be uterine contractions. The study's conclusion implies good interpretability. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size (Clinical Study): 42 women initially enrolled. 40 uterine activity (UA) registrations with sufficient usable data were assessed for performance evaluation.
- Data Provenance: The document does not specify the country of origin of the data. The study was an "observational clinical study," suggesting prospective data collection for the purpose of the study.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- Number of Experts: Three individual clinical investigators.
- Qualifications of Experts: They are referred to as "clinical investigators." No specific qualifications like "radiologist with 10 years of experience" are provided.
4. Adjudication Method for the Test Set
The adjudication method appears to be individual blinded assessment and annotation. The text states: "The tracings were reviewed by three individual clinical investigators, who were blinded to the technology used and the study subjects corresponding with the tracings. The clinical investigators assessed the interpretability of the tracings. In addition, they annotated the tracings by marking all deflections they assessed to be uterine contractions." This implies each expert independently reviewed and marked contractions, and the overall "performance" was assessed based on these individual assessments, likely compared against a gold standard (TOCO and IUPC data). It does not explicitly mention a consensus or arbitration process among the three experts.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and the Effect Size of How Much Human Readers Improve with AI vs Without AI Assistance
No, an MRMC comparative effectiveness study involving human readers with and without AI assistance was not explicitly described. The clinical study was designed to compare the PUREtrace™ device (which uses electromyography and processes the signal to display uterine activity) against established methods (tocodynamometry and intrauterine pressure catheter) and to assess its interpretability by human readers. The PUREtrace™ device itself is an "electromyography (EMG) device" that "converts [the EMG signal] into a measure for uterine activity and subsequently sent to a compatible fetal monitor where it is displayed as a tocogram." It's not presented as an AI-assisted human reading tool in this context, but rather a direct measurement and display device.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done
Yes, a standalone performance assessment of the PUREtrace™ device was done in the clinical study. The device's output (the displayed tocogram derived from EMG) was directly compared against TOCO and IUPC readings, and its interpretability was assessed by clinical investigators. The device is intended to non-invasively measure and display uterine activity, and its "performance" in doing so was evaluated independently.
7. The Type of Ground Truth Used
The ground truth used for comparison in the clinical study was:
- Tocodynamometry (TOCO): An external method for monitoring uterine contractions.
- Intrauterine Pressure Catheter (IUPC): An invasive, more direct and typically considered gold standard method for measuring uterine contraction strength and frequency.
The study simultaneously monitored uterine activity with PUREtrace™, TOCO, and IUPC.
8. The Sample Size for the Training Set
The provided document does not specify a training set sample size. The description focuses on the clinical performance testing of the device rather than its development or machine learning model training.
9. How the Ground Truth for the Training Set Was Established
Since a training set is not explicitly mentioned or described, the method for establishing its ground truth is not provided in this document.
§ 884.2720 External uterine contraction monitor and accessories.
(a)
Identification. An external uterine contraction monitor (i.e., the tokodynamometer) is a device used to monitor the progress of labor. It measures the duration, frequency, and relative pressure of uterine contractions with a transducer strapped to the maternal abdomen. This generic type of device may include an external pressure transducer, support straps, and other patient and equipment supports.(b)
Classification. Class II (performance standards).