(36 days)
Signos RT Bladder scanner projects ultrasound energy through the lower abdomen of a patient to obtain an image of the bladder that is used to non-invasively determine bladder volume. Users must have ultrasound training before using the device.
The Signostics Ltd SignosRT Bladder is a hand-held, diagnostic ultrasound system with an on-screen display. Its purpose is to acquire ultrasound echo data and display it in B-Mode on an LCD display to enable non-invasive volume measurement of a patients bladder.
Here's a breakdown of the acceptance criteria and study information for the SignosRT Bladder device, based on the provided FDA 510(k) summary:
Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Volume Accuracy (on a phantom) | Max of ±9.6% |
| Specified Volume Accuracy Standard | ±15% |
| Lateral Resolution (compared to predicate) | Identical to predicate SpeqRT Personal Ultrasound System |
| Axial Resolution (compared to predicate) | Identical to predicate SpeqRT Personal Ultrasound System |
| Compliance with Safety Standards | Complies with IEC 60601-1:2005, IEC 60601-2-37:2007, IEC 60601-1-2:2007, ISO 10993-5:2009, ISO 10993-10:2002, ISO 10993-10:2010, ISO 10993-12:2007, NEMA UD-2-2004 (R2009), NEMA UD-3-2004(R2009) |
| Software/Firmware Development & Verification | Developed and verified according to IEC 62304:2006 (Verification reports, traceability, and risk analysis demonstrate proper operation and mitigated risks) |
Study Details
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Sample size used for the test set and the data provenance:
- Test Set Sample Size: Not explicitly stated for specific imaging performance and measurement accuracy tests. The document mentions "bench tested for imaging performance and measurement accuracy" and "measured volume accuracy on a phantom," implying a phantom study rather than a human subject study for these metrics.
- Data Provenance: The studies were non-clinical (bench testing, phantom studies). The sponsor, Signostics Ltd, is based in Australia, but it's not explicitly stated where the specific bench tests were conducted.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- This information is not provided. Since the primary tests mentioned relate to phantom measurements, "experts" in the clinical sense (e.g., radiologists) would not be directly involved in establishing ground truth for these objective metrics.
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Adjudication method for the test set:
- This information is not provided. Not applicable for phantom and bench testing where objective measurements are compared against known values.
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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 is mentioned. This device is a diagnostic ultrasound system for bladder volume measurement, not an AI-assisted diagnostic tool for interpretation by human readers. The document states its purpose "is to acquire ultrasound echo data and display it in B-Mode on an LCD display to enable non-invasive volume measurement of a patients bladder."
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Yes, the performance characteristics like "measured volume accuracy on a phantom" and "measured lateral and axial resolution" are standalone performance metrics of the device itself (including its algorithms) without human intervention in the measurement process for those specific metrics. The device is a "bladder scanner projects ultrasound energy...to obtain an image of the bladder that is used to non-invasively determine bladder volume" and computes "an estimated bladder volume" via algorithms.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- For volume accuracy, the ground truth was based on phantom measurements. Phantoms are designed with known physical properties and dimensions, allowing for a precise and objective ground truth for physical measurements like volume.
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The sample size for the training set:
- This information is not explicitly provided. The document states the "algorithms used to calculate bladder volume are identical for the SignosRT Bladder and the predicate SpeqRT Personal Ultrasound System." This suggests that the bladder volume calculation algorithms were likely developed and "trained" (meaning optimized or validated, rather than machine learning training in the modern sense) on data from previous systems or general principles of ultrasound physics, but specific training set details are absent.
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How the ground truth for the training set was established:
- This information is not explicitly provided. Given that the algorithms are stated to be "identical" to a predicate device, their development and validation (establishing ground truth) would likely have been part of the predicate device's history, using methods such as controlled phantom studies or potentially clinical data where actual bladder volumes were measured by other means (e.g., catheterization) for correlation.
§ 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.