(49 days)
The Liver Incytes System is intended to provide estimates of tissue stiffness generated from shear wave speed measurements (40-70 Hz) and coefficient of attenuation. The device is indicated to non-invasively determine liver tissue stiffness and attenuation. These are meant to be used in conjunction with other clinical indicators in order to assist in clinical management of patients with liver disease.
Liver Incytes is a non-invasive ultrasound based device for measuring tissues stiffness and ultrasound attenuation in patients with chronic liver disease. The device uses ultrasound measurements of shear wave speed in the tissues to estimate stiffness. The attenuation is measured through the ultrasound signal itself.
The device is designed to be used at the point of care, in clinics and hospitals. The device is used by a medical profession, an employee of the clinic/hospital. The activation unit is placed under the patient, while lying supine on an exam bed. The activation unit vibrates causing shear waves within the liver of the patient. The ultrasound transducer is placed on the patient's skin, over the intercostal space, and is used to take volumetric scans of the liver while shear waves are occurring. From the scan data, the device calculates tissue stiffness and attenuation.
The provided text describes the regulatory clearance of the Sonic Incytes Liver Incytes, Model 1005 device. However, it does not contain specific details about a clinical study involving human patients to prove the device meets acceptance criteria for accuracy and performance for tissue stiffness and attenuation measurements.
The document primarily focuses on:
- Regulatory Clearance: FDA 510(k) clearance process.
- Device Description: What the Liver Incytes system is, how it works, and its intended use.
- Predicate Device: Comparison to the EchoSens FibroScan® for substantial equivalence.
- Non-Clinical Testing: Mentions electrical safety, electromagnetic interference, ultrasound, and phantom testing for accuracy and precision. It also mentions a "small cohort of healthy volunteers" for a usability study related to BMI, not for clinical performance against a ground truth.
- Standards Compliance: Lists various recognized consensus standards the device complies with.
Therefore, based only on the provided text, I cannot answer the questions directly related to a clinical study proving detailed performance against acceptance criteria in human subjects. The text explicitly states that only "non-clinical testing" was performed, which included phantom testing and a usability study on healthy volunteers.
Below, I will indicate where the information would typically be found in a complete study report and what is missing from this document.
Based on the provided text, the specific details for a clinical study with acceptance criteria and performance data are NOT available. The document focuses on non-clinical testing and substantial equivalence to a predicate device.
However, I can extract what is mentioned regarding testing and what would be required for the requested information:
Missing Information/Gaps from the Provided Text:
- Clinical Study for Performance: The text explicitly mentions "non-clinical testing" and a "usability study" on healthy volunteers. It does not describe a clinical performance study using patient data with established liver disease to validate the accuracy of tissue stiffness and attenuation measurements against a clinical ground truth.
- Specific Acceptance Criteria (for clinical performance): While general statements about accuracy and precision are made for phantom testing, no quantitative acceptance criteria for clinical performance (e.g., minimum sensitivity/specificity for liver fibrosis staging) are provided.
- Device Performance (Clinical): No specific metrics (e.g., AUC, sensitivity, specificity, accuracy, error margins) for how the device performed on human liver tissue stiffness and attenuation measurements are reported.
- Test Set Details: No information regarding a clinical test set (sample size, data provenance, ground truth establishment, adjudication) is provided.
- Training Set Details: No information regarding a training set for an AI/algorithm (if applicable, though this device seems to be a physical measurement system rather than a deep learning AI) is provided.
- MRMC Study: No mention of a multi-reader, multi-case study.
- Standalone Performance: No specific standalone performance metrics for the device on clinical data.
What is available in the provided document:
1. A table of acceptance criteria and the reported device performance (for non-clinical/phantom testing):
- Acceptance Criteria: Not explicitly stated as quantitative thresholds for clinical performance. For non-clinical tests, it states "The accuracy and precision of the device was tested and documented based on tests performed on phantoms with known elasticity and attenuation." This implies the acceptance criteria were that the device measurements on phantoms should align with the known values, but specific quantitative criteria are not given.
- Reported Device Performance: "The accuracy and precision of the device were found to be substantially equivalent to those of the predicate device and reference device (MRI Elastography)." No numerical performance metrics (e.g., mean absolute error, correlation coefficient, limits of agreement) are provided for either phantom or human studies. The human study mentioned was a "usability study" on healthy volunteers, not a performance study for liver stiffness/attenuation.
2. Sample size used for the test set and the data provenance:
- Test Set Sample Size:
- For phantom testing: Not specified, but likely refers to a set of phantoms.
- For human usability study: "a small cohort of healthy volunteers." The exact number is not provided, but it's explicitly for "usability" and "Body Mass Index from 25 to 43 kg/m2," not for clinical performance demonstration.
- Data Provenance: Not explicitly stated for any clinical performance data, as none are presented. The submitter is based in Vancouver, BC, Canada, but the location of any hypothetical clinical data collection is not mentioned. The usability study was on "healthy volunteers."
- Retrospective or Prospective: Not indicated, as no clinical performance study data is described.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not applicable/Not provided because no clinical performance test set with expert-established ground truth is described. For phantom testing, the ground truth is the "known elasticity and attenuation" of the phantoms.
4. Adjudication method for the test set:
- Not applicable/Not provided as no clinical test set requiring human adjudication is detailed.
5. 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, not mentioned. This document does not describe an AI-assisted interpretation system or a comparative effectiveness study involving human readers. The device measures physical properties (shear wave speed and attenuation).
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Yes, implicitly. The device itself provides the measurements. The performance "was tested and documented based on tests performed on phantoms." This would be a standalone performance, but the metrics are not provided in the document. No specific "algorithm only" performance for diagnosis from images is described; rather, the device directly outputs physical measurements.
7. The type of ground truth used:
- For non-clinical testing: "phantoms with known elasticity and attenuation."
- For a clinical performance study (which is not detailed here), common ground truths for liver stiffness could include liver biopsy (histopathology) or MRI Elastography (as referenced for substantial equivalence).
8. The sample size for the training set:
- Not applicable/Not provided. This document does not describe a machine learning algorithm that requires a training set for diagnostic tasks. The device measures physical properties.
9. How the ground truth for the training set was established:
- Not applicable/Not provided. As above, no machine learning training set is mentioned.
In summary, the provided FDA clearance letter and summary primarily address regulatory compliance and non-clinical testing for equivalence. It does not delve into the detailed results of a clinical performance study to establish specific acceptance criteria and device performance on human subjects for its intended diagnostic use.
§ 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.