(119 days)
This computed tomography system is intended to generate and process cross-sectional images of patients by computer reconstruction of X-ray transmission data.
The images delivered by the system can be used by a trained physician as an aid in diagnosis.
This CT system can be used for low dose lung cancer screening in high risk populations. *
- As defined by professional medical societies. Please refer to clinical literature, including the results of the National Lung Screening Trial (N Engl J Med 2011: 365:395-409) and subsequent literature. for further information.
The Siemens SOMATOM Drive is a Computed Tomography X- ray System, which features two continuously rotating tube-detector systems and functions according to the fan beam principle. The SOMATOM Drive produces CT images in DICOM format, which can be used by post-processing applications commercially distributed by Siemens and other vendors. The computer system delivered with the CT scanner is able to run the post processing applications optionally. syngo CT VA62A (SOMARIS/7 VA62A) is a command-based program used for patient management, data management, X-ray scan control, image reconstruction, and image archive/evaluation available on the SOMATOM Drive CT system.
Here's a breakdown of the acceptance criteria and supporting studies for the SOMATOM Drive, based on the provided FDA 510(k) summary:
1. Table of Acceptance Criteria and Reported Device Performance:
The document doesn't explicitly state numerical acceptance criteria in a dedicated table for the SOMATOM Drive (the new device being reviewed). Instead, it focuses on demonstrating that the SOMATOM Drive meets software specifications and performs comparably to predicate devices. The "reported device performance" is largely implicitly stated by concluding that "all of the software specifications have met the acceptance criteria" and "the SOMATOM Drive performs as intended."
However, we can infer some "acceptance criteria" through the lens of what was tested and compared to predicate devices:
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Safety: Conformance to recognized standards. | Claims conformance to IEC 60601-1/A2: 2005; IEC 60601-2-44:2009 +A1:2012; XR-29: 2013; ISO/IEC 14971:2007; IEC 62304: Ed. 1.0 2006, IEC 61223-2-6: 2006, 61223-3-5: 2004, XR 25, ISO/IEC 10918-1: 1994, DICOM NEMA PS 3.1 - PS 3.20. Risk analysis completed, hazards mitigated, and risk control implemented. |
| Software Functionality: All software specifications met. | "The test results show that all of the software specifications have met the acceptance criteria." "Verification and validation testing of the device was found acceptable to support the claim of substantial equivalence." "The performance data demonstrates continued conformance with special controls for medical devices containing software." |
| Image Performance: Comparable to predicate devices. | "Non-clinical tests (integration and functional), including phantom test were conducted during the SOMATOM Drive product development." "The non-clinical test data demonstrates that the SOMATOM Drive performance is comparable to the predicate devices that are currently marketed for the same intended use." |
| Dosimetry: Met during product development. | "Non clinical tests, including dosimetry and image performance, were conducted for the SOMATOM Drive during product development." |
| New Features (X-ray Tube/kV Steps): Function as intended. | Higher mA at lower kV levels (70kV, 80kV). Consistent 10kV steps (70-140kV), adding 90kV, 110kV, 130kV. Implied to function correctly based on overall software/performance claims. |
| New Features (Tube Collimator): Function as intended. | Includes Tin Filter on collimator of both X-ray tubes (vs. one on predicate). Implied to function correctly. |
| New Features (Dual Power Mode): Function as intended. | Allows use of both tubes at same kV with routine pitch and full detector width, doubling mA. Implied to function correctly, compared to predicate which only allowed half detector width. |
| Clinical Performance for Dual Source Dual Power mode: Demonstrated. | "Clinical images were evaluated to demonstrate performance for Dual Source Dual Power mode." |
| Effectiveness: Supported by clinical literature for lung cancer screening. | Refers to the National Lung Screening Trial (NLST) for low-dose lung cancer screening. (This is for the indication for use, not the device's technical performance itself). |
2. Sample Size Used for the Test Set and Data Provenance:
- Test Set Sample Size: Not explicitly stated for specific non-clinical tests. The document mentions "clinical images were evaluated" for Dual Source Dual Power mode, but the number of images/patients is not provided.
- Data Provenance:
- Non-clinical/Software Testing: Conducted "during product development." This implies controlled, in-house testing, likely in Germany where the manufacturing site is located (Siemens Healthcare GmbH, Forchheim, Germany).
- Clinical Images: "Clinical images were evaluated" suggests retrospective or newly acquired images for validation. No specific country of origin is mentioned.
- National Lung Screening Trial (NLST): A multi-center randomized controlled trial conducted in the United States. The study started in August 2002 and completed in October 2010.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications:
- For the device's technical performance (non-clinical tests, software evaluation):
- No information is provided about expert involvement for establishing ground truth for the test set used in non-clinical or software testing. These typically rely on defined engineering specifications and quantitative measurements.
- For the clinical images evaluated for Dual Source Dual Power mode:
- No information provided on experts or their qualifications for evaluating these images.
- For the NLST reference:
- The NLST involved multiple radiologists at participating centers. The interpretation task for CT was to detect lung nodules of 4mm diameter or greater. The expertise of these radiologists would be broad, as it was a large-scale clinical trial. The document doesn't detail their specific years of experience or sub-specialties beyond being "trained physicians" in the general indications.
4. Adjudication Method for the Test Set:
- No specific adjudication method (e.g., 2+1, 3+1) is mentioned for any of the tests conducted for the SOMATOM Drive itself.
- The NLST, as a large clinical trial, would have had its own established protocols for interpretation, consensus, and potentially adjudication to establish ground truth for its primary endpoints, but this is not detailed in the 510(k) summary regarding the device's performance.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
- No MRMC comparative effectiveness study was done regarding human readers improving with AI vs. without AI assistance.
- The SOMATOM Drive is a CT scanner, not an AI-assisted diagnostic tool. The document focuses on the hardware and reconstruction software performance, not on AI for interpretation.
6. Standalone Performance (Algorithm Only without Human-in-the-Loop):
- Yes, a standalone performance assessment was conducted for the device's capabilities. The document states:
- "Nonclinical tests, including dosimetry and image performance, were conducted for the SOMATOM Drive during product development."
- "The test results show that all of the software specifications have met the acceptance criteria."
- "Non-clinical tests (integration and functional), including phantom test were conducted during the SOMATOM Drive product development."
- These tests assess the system's output (images, dose measurements) directly against specified criteria, effectively evaluating its "standalone" algorithmic and hardware performance.
7. Type of Ground Truth Used:
- For non-clinical/software performance:
- Ground truth was based on engineering specifications and phantom measurements. These are objective, quantifiable standards for image quality, dose, and system functionality.
- For clinical images for Dual Source Dual Power mode:
- Not explicitly defined, but implied to be based on clinical evaluation of the images by unstated evaluators.
- For the NLST reference (supporting the Indication for Use for lung cancer screening):
- The NLST's ground truth for lung cancer detection and mortality reduction would have been based on pathology results for confirmed cancers and long-term outcomes data (mortality).
8. Sample Size for the Training Set:
- Not applicable / Not provided. The SOMATOM Drive is a CT imaging system. While it uses complex algorithms for image reconstruction (e.g., ADMIRE, iMAR), these are typically engineered using physics-based models and iterative refinement, not "trained" on large datasets in the way modern deep learning AI models are. Therefore, there isn't a "training set" in the context of machine learning. The algorithms are part of the system's core functionality.
9. How the Ground Truth for the Training Set Was Established:
- Not applicable. As above, the system uses algorithms that are largely model-based and optimized through engineering principles, rather than being trained on a labeled dataset with a "ground truth" in the AI sense.
§ 892.1750 Computed tomography x-ray system.
(a)
Identification. A computed tomography x-ray system is a diagnostic x-ray system intended to produce cross-sectional images of the body by computer reconstruction of x-ray transmission data from the same axial plane taken at different angles. This generic type of device may include signal analysis and display equipment, patient and equipment supports, component parts, and accessories.(b)
Classification. Class II.