(70 days)
The SPY Fluorescent Imaging System is an imaging system used in capturing and viewing fluorescent images for the visual assessment of blood flow as an adjunctive method for the evaluation of tissue perfusion, and related tissuetransfer circulation in tissue and free flaps used in plastic, micro- and reconstructive surgical procedures.
The SPY Fluorescent Imaging System used in plastic, micro, and reconstructive surgery indication consists of 2 components: the SP2001 Imaging Device and the SPY Paq. The SP2001 Imaging Device consists of an imaging head containing a charge coupled device (CCD) camera, a laser light source, motion sensor, and distance sensor attached via an articulating arm to a mobile cart. The mobile cart contains a flat panel display, a computer with keyboard and optical mouse, an electronics enclosure, and a printer. The SPY System provides the surgeon with the capability to view, record, and replay fluorescent images of blood flow in vessels and organs. A laser light source is used to illuminate the area of interest. In order to obtain the images, ICG is injected intravenously through the central or peripheral venous line. While the ICG is passing through the vessels, the absorption of laser light causes excitation of the ICG dye, followed by the emission of infrared energy. A CCD camera of the SP2000 Imaging Device captures the infrared emission, resulting in a fluorescent image of blood flow and related tissue perfusion. These images are used to evaluate the integrity of native and grafted vasculature and blood flow in the organs. The SP2001 Imaging Device represents minor modifications of the SP2000 Imaging Device: The maximum recording time for image sequences captured has been extended to 60 seconds from the 34 seconds of the SP2000 Imaging Device. An ability to move the SP2001 camera head in horizontal plane during image sequence acquisition has been implemented. A variable Laser Power Attenuator has been added to the device to permit laser illumination at power levels lower or equal to the laser power level of the SP2000 Imaging Device. New HELIOS software has been developed to support the SPY System in its plastic, micro-, and reconstructive surgery indication.
Here's a breakdown of the acceptance criteria and study information for the SPY® Fluorescent Imaging System (SP2001 Imaging Device) based on the provided 510(k) summary:
1. Table of Acceptance Criteria and Reported Device Performance
It's important to note that this 510(k) submission (K073088) is for a device modification (SP2001) of an already cleared device (SP2000). The primary focus of the testing described is to demonstrate that the modifications do not introduce any new safety concerns and that the modified device remains substantially equivalent to its predicate device, while enhancing functionality for plastic, micro-, and reconstructive surgery. Therefore, the "acceptance criteria" are generally related to safety and the ability to produce high-quality images as demonstrated by previous studies and the current assessment of the modifications.
| Acceptance Criteria (Inferred from testing and safety claims) | Reported Device Performance |
|---|---|
| Safety - Electrical, EMC, Laser Standards Compliance: Device must conform to relevant safety standards. | The SPY System "successfully met all of the requirements for these standards" (IEC 60601-1, UL2601-1, IEC 60601-1-2, 21 CFR 1040, ANSI Z136.3, ANSI Z136.1). |
| Safety - Thermal Damage (Human): Use of the SPY System and its modifications should not cause thermal damage to the area of interest, even after repeated imaging sequences. | "Use of the SPY® System does not cause any thermal damage to the area of interest, even after repeated imaging sequences." This is supported by pig studies showing no increase in myocardial tissue temperature and the calculated exposure for SP2001 (31.2 mW/cm2) being well below the maximum permissible exposure (MPE) of 326 mW/cm2 established by ANSI for skin exposure. The extended recording time (60 seconds) does not affect the MPE value. |
| Safety - Physiological Effects (Human): No adverse acute or long-term cellular, renal, hepatic, or cardiovascular effects (e.g., changes in ECGs, arterial pressures) from device use. | "The SPY System has been used in over 7000 vascular procedures in humans and there have been no reports of adverse acute or long-term cellular, renal or hepatic effects." Additionally, for the heart, "there were no changes in electrocardiograms or arterial pressures during and/or following the use of SPY System." Pig studies supported these findings: "It was possible to perform multiple imaging sequences with no detrimental effects on heart function, coronary flow or peripheral pressure." and "There were no acute or long-term cellular effects of using the SPY System." and "There were no acute or long-term renal or hepatic effects of using the SPY System." |
| Image Quality & Resolution (Human): The device should produce high-quality and resolution images of the entire vascular bed of the area of interest, including the ability to visualize blood flow, tissue perfusion, and related tissue-transfer circulation. The SP2001 enhancements should support this for larger/extended areas (e.g., flaps). | "The data from intra-operative imaging in CABG, cardiovascular, as well as in plastic, micro-, reconstructive surgery demonstrated the clinical utility of the device in producing high quality and resolution images of the entire vascular bed of the area of interest." The ability to move the camera head horizontally and extended recording time in SP2001 implicitly support imaging larger/extended areas to view the entire cycle of blood flow. Pig studies showed: "The SPY System was able to acquire high quality images of the entire vascular bed on each area of interest." and "It was possible to visualize all of the coronary beds with high quality images even when the heart was in a vertical position for visualizing posterior arteries." and "The SPY System is capable of imaging through the skin to provide a visual assessment of dermal and subdermal blood flow." |
| Clinical Utility/Effectiveness (Human): The system should provide useful clinical information, such as identifying the need for graft revision (in CABG as an example of previous indications and general utility). | "The literature reports that the SPY System was able to non-invasively, quickly and safely identify 17 conduits in 311 patients that required revision during the surgical procedures. In all cases the lack of patency was visualized clearly by the SPY System..." This is from prior clearances but supports the general clinical utility of the SPY system design. |
| Functional Enhancements (SP2001): The modifications (e.g., extended recording time, horizontal camera movement, variable laser power, new software) should provide increased functionality without compromising safety or effectiveness. | "The modifications of the SP2000 Imaging Device were introduced to provide the end users the increased functionality for using the SPY System in the plastic, micro-, and reconstructive surgery." The submission states "the modifications do not introduce any additional or new concerns regarding the safety and use of the device." The HELIOS™ software is described as concentrating on a suitable interface and not altering how the device is used, implying it maintains the previous functionality and safety. |
2. Sample Sizes Used for the Test Set and Data Provenance
Since this filing is primarily about a modification to an already cleared device and relies heavily on previously submitted data and widespread clinical use, there isn't a single "test set" in the traditional sense for this specific 510(k). The data provenance is a combination:
- Human Clinical Experience:
- Sample Size: Over 7000 vascular procedures (cumulative across all indications for prior clearances).
- Data Provenance: Commercially available in the United States, Japan, Europe, and Canada. This indicates both prospective and retrospective data collection over time in a real-world clinical setting.
- Specific Example from Literature Review: 311 patients where 17 conduits required revision. This is from published peer-reviewed articles.
- Animal Studies (for original 510(k) and foundational safety):
- Sample Size: Six pig studies.
- Data Provenance: Not specified, but likely conducted by the manufacturer or research partners. These were "to support the original traditional 510(k) premarket notification" (K042961).
- In Vitro Testing: Not applicable to "test set" in this context, but refers to laboratory testing for standards compliance (electrical, EMC, laser).
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The concept of a formalized "ground truth" derived from a specific number of experts for a single test set, as might be common in AI/algorithm validation, is not explicitly detailed in this 510(k) for the SP2001 device modification.
- Human Clinical Experience: The "ground truth" arises from the clinical outcomes and the surgical decisions made by operating surgeons based on the visual assessment provided by the SPY System. For instance, in the 311 patients where 17 conduits required revision, the surgeon's decision to revise implicitly serves as an "expert ground truth" that the device correctly informed. The "experts" are the surgeons using the device. Their qualifications are not specified beyond being "surgeons" performing vascular, plastic, micro-, and reconstructive procedures.
- Animal Studies: The "ground truth" would have been established by direct observation and physiological measurements in the pig studies (e.g., no detrimental effects on heart function, coronary flow, myocardial tissue temperature). The experts would be the researchers and veterinarians conducting those studies.
4. Adjudication Method for the Test Set
Again, given the nature of a device modification relying on existing clinical experience, a formal adjudication method (like 2+1 or 3+1 used in AI studies) for a dedicated "test set" is not described.
- Clinical Use: Clinical decisions in surgery are inherently "adjudicated" by the practicing surgeon's judgment and experience, often incorporating other diagnostic information, physical examination, and surgical observation, not solely the device output. The device is described as an "adjunctive method."
- Literature Reports: The reported clinical utility from peer-reviewed articles would reflect consensus findings within the broader medical community, implying a form of expert review and publication acceptance.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done
No, an MRMC comparative effectiveness study that specifically measures the effect size of human readers improving with this device (SP2001) vs. without AI assistance is not explicitly mentioned or described in this 510(k) summary.
The SPY System is an imaging device that provides visual information to the surgeon, not an AI-driven diagnostic algorithm that provides interpretation or assistance in the way modern AI tools do. Its improvements are primarily in extending the visual capabilities (longer recording, wider field of view) for the human user.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was Done
No, a standalone performance study in the context of an algorithm or AI is not applicable or described. The SPY® Fluorescent Imaging System is an imaging tool designed for human-in-the-loop visual assessment. It captures images; it does not interpret them standalone.
7. The Type of Ground Truth Used
The ground truth used is predominantly a combination of:
- Clinical Outcomes/Surgical Decision-Making: For humans, the ultimate "ground truth" for assessing tissue perfusion and blood flow is whether the surgical procedure is successful, whether revisions are needed, and the subsequent patient outcomes. Decisions made by surgeons based on the images are a direct form of clinical ground truth about the physiological state.
- Physiological Measurements/Direct Observation (Animal Studies): In the pig studies, the ground truth was established by direct physiological measurements and observations of heart function, coronary flow, myocardial temperature, etc.
- Pathology/Histology/Outcomes Data: While not explicitly stated for every case, the implications of successful graft revisions (reducing myocardial infarctions, morbidity, mortality) suggest that long-term outcomes and potentially pathological findings (e.g., if a graft failed) would serve as ultimate ground truth checks.
8. The Sample Size for the Training Set
No training set is mentioned as this device is not an AI/ML algorithm requiring a training set. It is a hardware and software system for image acquisition and display.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no training set for an AI/ML algorithm.
§ 892.1600 Angiographic x-ray system.
(a)
Identification. An angiographic x-ray system is a device intended for radiologic visualization of the heart, blood vessels, or lymphatic system during or after injection of a contrast medium. This generic type of device may include signal analysis and display equipment, patient and equipment supports, component parts, and accessories.(b)
Classification. Class II.