(15 days)
New device: The BladderMass™ BVM 6500 is intended to project ultrasound energy through the lower abdomen of the nonpregnant patient to obtain an image of the bladder and uses that image to calculate the bladder volume and bladder wall mass noninvasively. The BladderMass BVM 6500 is contraindicated for fetal use and for use on pregnant patients.
The Diagnostic Ultrasound BladderMass BVMTM 6500 Ultrasound System is a hand-held, battery powered, software controlled ultrasound system used to acquire and display real time B-mode images of the bladder. The system is intended to non invasively monitor bladder volume on an intermittent basis. The system is an effective, low cost, simple option for use in a clinical hospital or nursing home setting or for home use under medical supervision.
Here's an analysis of the acceptance criteria and the study that proves the device meets them, based on the provided text:
Acceptance Criteria and Device Performance
The document primarily focuses on demonstrating substantial equivalence to a predicate device (BladderScan™ BVI 6100) and proving the accuracy of the new "bladder wall mass" measurement. The core of the acceptance criteria for this new feature is explicitly stated as accuracy when compared to known dimensions of phantoms.
| Acceptance Criteria (Implicit for Bladder Wall Mass) | Reported Device Performance |
|---|---|
| Accuracy of BladderMass BVM™ 6500 in measuring bladder wall mass compared to known dimensions (as claimed in 0270-1238-xx-55, though specific values are not provided in this extract). | The BladderMass BVM™ 6500 Ultrasound System's measurements of bladder wall mass were compared to "expected results derived from the NIST traceable measurements" of tissue-equivalent phantoms. Additionally, these measurements were compared with those obtained from "standard ultrasound systems, such as the Sonosite 180." The overall conclusion states: "Accuracy has been demonstrated by comparing CIRS measurements to the measurements of the Diagnostic Ultrasound BladderMass BVM™ 6500 Ultrasound System." While specific numerical performance (e.g., mean absolute error, percentage deviation) is not provided in this summary, the statement "Accuracy has been demonstrated" indicates that it met the (unspecified) acceptance threshold for this new functionality. |
| Substantial Equivalence to Predicate Device (Diagnostic Ultrasound BladderScan™ BVI 6100) for bladder volume and imaging. | "All clinical and non clinical testing of the Diagnostic Ultrasound BladderMass BVM™ 6500 Ultrasound System indicate that the Diagnostic Ultrasound BladderMass BVM™ 6500 Ultrasound System is substantially equivalent to the Diagnostic Ultrasound BladderScan™ BVI 6100 Ultrasound System, and all acoustic measurements remain within Preamendment limits." This implies that the device met the performance and safety characteristics of the predicate for its shared intended uses. |
Study Information
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Sample size used for the test set and the data provenance:
- Test Set Sample Size: Not explicitly stated as a number of phantoms. The study used "different urine volumes and thus different bladder wall thickness measurements" created by filling balloons with varying amounts of urine mimicking material.
- Data Provenance: The test set data was generated in a controlled laboratory setting using "tissue equivalent phantoms with known dimensions" built by a third-party vendor, Computerized Imaging Reference Systems (CIRS), which is stated to be known for supplying medical imaging phantoms. This is a prospective method using manufactured phantoms, not human data.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Number of Experts: Not applicable. The ground truth was established by NIST traceable measurements of the physical phantoms themselves. No human experts were involved in defining the ground truth for this specific test.
- Qualifications of Experts: Not applicable.
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Adjudication method (e.g., 2+1, 3+1, none) for the test set:
- Not applicable. The ground truth was based on physical measurements of the phantoms, not human interpretations requiring adjudication. The device's measurements were then compared directly to these known physical measurements.
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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. The study described focuses on the standalone performance of the device's bladder wall mass measurement capability against phantoms. No human readers or AI assistance for human readers are mentioned.
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If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- Yes. The described study is a standalone performance evaluation. The device (BladderMass BVM™ 6500) automatically computes the bladder volume and bladder wall mass. Its measurements are then compared directly to the known "ground truth" of the phantoms.
- The text explicitly states: "The Diagnostic Ultrasound BladderMass BVM™ 6500 Ultrasound System takes measurements of the bladder wall and calculates the bladder wall mass." This confirms a standalone algorithm performance evaluation.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- The ground truth used was physical measurements of high-precision, NIST-traceable phantoms. These phantoms were designed to mimic the bladder and surrounding tissue, with exact dimensions known from the manufacturing process.
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The sample size for the training set:
- Not specified. The document does not provide details about a training set for the algorithm, only the testing methodology. As the device was approved in 2003, it's possible its algorithms were based on more traditional signal processing and image analysis techniques rather than machine learning requiring large, dedicated training datasets as understood today.
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How the ground truth for the training set was established:
- Not specified, as no training set details are provided in this summary.
§ 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.