(21 days)
The SPY Cystoscopes/Hysteroscopes are intended to provide visualization in general urological and gynecological surgery through the minimally invasive approach, by utilizing natural orifices to access the surgical site.
The SPY Cystoscope/Hysteroscope is part of Stryker's rigid endoscope product portfolio. The SPY Cystoscope/Hysteroscope is an optical instrument used to visualize or image a patient's anatomy during minimally invasive, endoscopic procedures for examination, diagnosis or therapy. The SPY Cystoscope/Hysteroscope transmits light in the visible spectrum to illuminate the anatomy, then forms and relays the image of the surgical site to a camera system for image processing and display.
Based on the provided FDA 510(k) clearance letter for the SPY Cystoscope/Hysteroscope (K252012), here's a description of the acceptance criteria and the study that proves the device meets them:
Important Note: The provided document is a 510(k) clearance letter, which summarizes the information submitted by the manufacturer. It does not contain the full details of the testing performed. Therefore, some of the requested information (especially regarding specific test methodologies, exact sample sizes for training/test sets, expert qualifications, and ground truth establishment details) is not explicitly stated in this summary. I will highlight what is present and what is inferred based on standard regulatory practices for this type of device.
Study Proving Device Meets Acceptance Criteria
The study performed to demonstrate the device meets acceptance criteria was a non-clinical performance and safety evaluation, primarily involving bench testing. This approach is common for optical, non-diagnostic devices like endoscopes, where functionality can be objectively measured. The submission explicitly states, "The subject device does not require clinical studies to support the determination of substantial equivalence."
1. Table of Acceptance Criteria and Reported Device Performance
The letter outlines the types of non-clinical tests performed, implying these are the areas for which performance criteria were established. While the letter doesn't provide specific numerical acceptance thresholds or the exact measured values, it states that the testing "demonstrates the device conforms with design input requirements, user needs and intended uses."
| Acceptance Criteria Category (Implied) | Reported Device Performance Summary |
|---|---|
| Optical Performance Characteristics: | • Demonstrates conformity with design input requirements, user needs, and intended uses. |
| • Comparative bench top testing shows subject and reference device's optical performance are equivalent. | |
| Optimal Object Distance (Depth of Field) | Testing performed. |
| Fiber Transmission | Testing performed. |
| Optical Transmission | Testing performed. |
| Distortion | Testing performed. |
| Modulated Transfer Function (MTF) Center and Fringes | Testing performed. |
| Vignetting | Testing performed. |
| Field of View (FOV) | Testing performed. |
| Apparent Field of View (AFOV) | Testing performed. |
| Image Runout | Testing performed. |
| Chromatic Aberration | Testing performed. |
| Contrast Testing | Testing performed. |
| Mechanical Attributes: | • Demonstrates conformity with design input requirements, user needs, and intended uses. |
| Hardware Compatibility (Stryker and Karl Storz series models) | Testing performed. |
| Safety & Risk Assessment: | • Risk management activities concluded that the benefits associated with the use of the device outweigh the residual risk; the overall residual risk is acceptable. |
| Packaging Qualification: | • A summary of packaging qualification is provided. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: The document does not specify the exact sample sizes (e.g., number of devices tested) for the non-clinical bench tests. For most bench testing, typically a representative sample or a statistically significant number of production units are tested to ensure consistency and meet specifications.
- Data Provenance: This was non-clinical bench testing, not human data. Therefore, concepts like "country of origin of the data" or "retrospective/prospective" do not directly apply to the primary performance testing.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
- Not Applicable: Since this device is an optical instrument for visualization (not an AI/diagnostic algorithm interpreting images), and the testing was non-clinical bench testing, "experts" in the sense of clinical reviewers establishing ground truth for a test set (e.g., radiologists reading images) were not involved in the direct performance evaluation of the device's optical properties. The "ground truth" for these tests would be the established engineering and optical performance specifications.
4. Adjudication Method for the Test Set
- Not Applicable: Given that the performance evaluation was based on objective, quantitative bench testing (e.g., measuring MTF, FOV, transmission), there was no need for human adjudication of test results in the way one would adjudicate case labels for diagnostic AI. The results are based on instrumental measurements compared against specifications.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
- No: The document explicitly states: "The subject device does not require clinical studies to support the determination of substantial equivalence." An MRMC study is a clinical study involving human readers. Therefore, no MRMC study was performed or required for this 510(k) clearance.
- Effect Size: Not applicable as no MRMC study was conducted.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done
- Not Applicable: This device is a physical optical instrument (cystoscope/hysteroscope), not an AI algorithm. Therefore, the concept of "standalone algorithm performance" does not apply. Its performance is its ability to transmit light and form an image according to specifications, which was evaluated via bench testing.
7. The Type of Ground Truth Used
- Engineering/Optical Specifications: The ground truth for this device's performance evaluation was established through pre-defined engineering and optical specifications (design input requirements) that the device must meet (e.g., a specific MTF value, a defined FOV range, acceptable levels of distortion, etc.). These specifications are typically derived from industry standards, predicate device performance, and user needs.
8. The Sample Size for the Training Set
- Not Applicable: This is a hardware device; thus, it does not have a "training set" in the context of machine learning. The design and manufacturing processes are refined through engineering, prototyping, and iterative testing, not through training on data.
9. How the Ground Truth for the Training Set Was Established
- Not Applicable: As there is no "training set," this question is not relevant for this device. Ground truth for hardware development is established through engineering design principles, materials science, and manufacturing tolerances.
Summary of Approach:
The clearance for the SPY Cystoscope/Hysteroscope relied on a "Comparison to Predicate" approach, underpinned by extensive non-clinical bench testing to demonstrate that the new device's different technological characteristics (specifically smaller outer diameter and increased field-of-view) "do not raise different questions of safety or effectiveness" compared to the predicate devices. The safety and effectiveness were established by confirming the device met its design specifications for various optical and mechanical parameters.
§ 884.1690 Hysteroscope and accessories.
(a)
Identification. A hysteroscope is a device used to permit direct viewing of the cervical canal and the uterine cavity by a telescopic system introduced into the uterus through the cervix. It is used to perform diagnostic and surgical procedures other than sterilization. This generic type of device may include obturators and sheaths, instruments used through an operating channel, scope preheaters, light sources and cables, and component parts.(b)
Classification. (1) Class II (performance standards).(2) Class I for hysteroscope accessories that are not part of a specialized instrument or device delivery system; do not have adapters, connectors, channels, or do not have portals for electrosurgical, laser, or other power sources. Such hysteroscope accessory instruments include: lens cleaning brush, cannula (without trocar or valves), clamp/hemostat/grasper, curette, instrument guide, forceps, dissector, mechanical (noninflatable), and scissors. The devices subject to this paragraph (b)(2) are exempt from the premarket notification procedures in subpart E of part 807 of this chapter, subject to the limitations in § 884.9.