BLUE 400 and BLUE 400 S are accessories to the surgical microscope and allow the fluorescence observation of fluorophores with an excitation peak between 400 nm and the fluorescence emission observation comprising the spectrum in a spectral band of 620 - 710 nm.

The ZEISS BLUE 400 and BLUE 400 S are surgical microscope accessories used in fluorescent visualization of suspected grade III and IV gliomas during neurosurgery.

Device Description

The BLUE 400 and BLUE 400 S are fluorescence accessories to qualified surgical microscopes, intended to allow intraoperative viewing of malignant glioma tissue grade III and IV under fluorescence. The overall system is comprised of excitation (illumination) and emission (observation) filters to detect fluorescence and are optimized in conjunction with the drug to pass light between 620 – 710 nanometers. The BLUE 400 S filters allow the surgical microscope to produce excitation light in a wavelength range covering at least 400 - 410 nanometers that excites an approved optical imaging agent and enables the surgeon to observe the emitted fluorescent signal in the oculars or on a display. Fluorescence of marked brain tissue helps visualization of tissue associated with Grade III & IV glioma during neurosurgeries.

Compared to the blue visualization of the surrounding non-fluorescent tissue in the BLUE 400 image, BLUE 400 S is designed to visualize the surrounding nonfluorescent tissue more similar to white light impression, while tumor visualization of grade III and IV glioma remains consistent. With the visualization of non-fluorescent anatomy in an almost white light impression, BLUE 400 S is expected to allow PplX visualization with less frequent switching between fluorescence and white light imaging modes.

BLUE 400 and BLUE 400 S can be installed only into qualified ZEISS surgical microscopes. For these accessories to be used with a qualified ZEISS surgical microscope, the critical components of the surgical microscope need to fulfill the clinically relevant parameters for the Indications for Use of BLUE 400 and BLUE 400 S.

AI/ML Overview

The provided FDA 510(k) summary (K240215) describes the Carl Zeiss Meditec AG BLUE 400 and BLUE 400 S accessories to surgical microscopes for fluorescent visualization of grade III and IV gliomas.

Here's an analysis of the acceptance criteria and study information:

1. Table of Acceptance Criteria and Reported Device Performance

The submission primarily focuses on demonstrating substantial equivalence to a predicate device (BLUE 400, K211346) through technical and performance testing, rather than defining explicit clinical acceptance criteria in terms of sensitivity, specificity, or other diagnostic measures for identifying gliomas. The acceptance criteria used are in the form of "Passed" results for various technical and functional tests.

Test Description	Acceptance Criteria (Implied by "Passed" result)	Reported Device Performance
Brightness of the fluorescence ocular image	Image brightness of ZEISS fluorescence target at ocular plane at 250 mm working distance meets specified target. (Specific value not provided here, but "Passed")	Passed
Irradiance	Excitation light density in the object plane meets specified target. (Specific value not provided here, but "Passed")	Passed
Spatial resolution of the ocular image	Spatial resolution measured with test target in white light mode at min/max magnification and 200mm working distance meets specified target. (Specific value not provided here, but "Passed")	Passed
Excitation wavelength (of the microscope)	Excitation wavelength range of PpIX (400 nm to 410 nm) is covered by both BLUE 400 and BLUE 400 S options. (Specific quantitative range achieved for subject device: BLUE 400: 400-430nm; BLUE 400 S: 398-457nm for 50% edges)	Passed
Excitation filter	Optical filter specification of excitation filter meets requirements.	Passed
Emission wavelength (of the microscope - ocular image)	Design review/measurement of spectrum at ocular plane meets requirements. (Specific quantitative range achieved for subject device: BLUE 400: >450nm; BLUE 400 S: 540-728nm for 50% edges)	Passed
Emission wavelength (of the microscope - video image)	Design review/measurement of spectrum at ocular plane meets requirements.	Passed
Emission filter	Optical filter specification of emission filter meets requirements.	Passed
Non-mirrored video image	Visual inspection with test target in white light mode confirms non-mirrored image.	Passed
Non-rotated video image	Visual inspection with test target in white light mode confirms non-rotated image.	Passed
Non-deformed video image	Visual inspection of geometric distortions of a test target with a circle in white light mode shows no significant deformation.	Passed
Centered video image	Visual inspection and measurement with a test target in white light mode confirms centered image.	Passed
Photometric resolution of video image	Grey value resolution test with photometric resolution test target in white light mode meets requirements.	Passed
Signal-to-noise ratio of the video image (sensitivity)	Signal-to-noise ratio of video image of a fluorescent target at a given signal value meets requirements.	Passed
Latency of the video image	Video latency in white light mode meets requirements.	Passed
Spatial resolution of the video image	Spatial resolution measured with test target in white light mode meets requirements.	Passed
Spectrum of the Illumination Source (TS1)	Irradiance spectrum (250 nm - 1020 nm, mW/cm²) of illumination source measured and verified with spectrometer prior to excitation filter module application.	Passed
Maximum Power and Irradiance of the Illumination Source (TS2)	Maximum output power and irradiance of illumination sources measured and verified with power meter at end of microscope light guide prior to excitation filter module application.	Passed
Irradiance Spectrum of the Excitation Light and Spectral Response of the Excitation Filter (TS3)	Irradiance spectrum (250 nm - 1020 nm) of illumination light after excitation filter module measured; 50% decrease edges of blue excitation peak calculated and found acceptable.	Passed
Maximum Excitation Power and Power Density (TS4)	Maximum power (mW) and power density (mW/cm²) of excitation light measured at multiple working distances/zoom settings. Subject device measurements comparable to predicate device.	Passed
Optical Path Loss (TS5)	Detectable light output and total losses in relation to device working distance and zoom setting, calculated by dividing output signal at eyepiece by illumination signal at focal plane for the same zoom setting, found acceptable.	Passed
Spectrum of the Emission Filter (TS6)	Spectrum (350 nm – 1050 nm) of emission filter integrated in surgical microscope measured; 50% edge of spectrum calculated and found acceptable.	Passed
Homogeneity of the Excitation Light at the Focal Point (TS7)	Reflected signal from white sheet of paper at 30 cm working distance imaged, and intensity profile calculated to demonstrate homogeneity of excitation light, found acceptable.	Passed
System Sensitivity (TS8)	BLUE 400: Fluorescence signal in eyepiece for ZEISS BLUE 400 fluorescent target at 22.5 cm working distance comparable to predicate device. BLUE 400 S: Ratio of reconstructed fluorescence signal to reconstructed remission spectrum (corresponding to fluorescence to emission light ratio) found acceptable. (Specific details of "acceptable" criteria are not provided)	Passed
Pre-Operative Phantom Test (TS9)	ZEISS BLUE 400 test phantom (with one fluorescent area) suitable for pre-operative checks of a surgical microscope; imaged by camera and observed through eyepiece.	Passed
Spectrum of the Camera Filter (TS10)	Spectrum at camera interface measured to demonstrate camera filter blocks near infrared and infrared leakage of excitation light to the camera.	Passed
Special Controls Testing	Performance with and without cover glass met defined specifications.	Passed

2. Sample Size Used for the Test Set and Data Provenance

The document describes non-clinical performance testing (bench testing) using "ZEISS fluorescence target," "spatial test target," "photometric resolution test target," "test target with a circle," "white sheet of paper," and "ZEISS BLUE 400 test phantom."

Sample Size: Not explicitly stated for each test, but implied to be sufficient for bench validation of optical and system parameters. These are physical components being tested, not patient samples.
Data Provenance: The tests are described as bench/non-clinical system testing. This indicates the data was generated in a lab setting by the manufacturer (Carl Zeiss Meditec AG, Germany, based on manufacturer details). It is not derived from patient data.
Retrospective/Prospective: Not applicable as it's bench testing, not clinical studies.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications

Not applicable. This submission relies on technical bench testing against predefined engineering specifications and comparison to a legally marketed predicate device. The "ground truth" for these tests is the physical measurement of optical properties and system functions, validated against engineering requirements, not clinical expert consensus on patient data.

4. Adjudication Method for the Test Set

Not applicable. Adjudication methods like "2+1" or "3+1" are typically used in clinical studies for establishing ground truth (e.g., determining disease presence in an image) based on multiple readers. This submission describes bench testing where the outcome is a "Passed" result based on meeting physical specifications.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done

No, an MRMC comparative effectiveness study was not done. The submission focuses on non-clinical technical equivalence and performance of the device's optical and system functions. It does not evaluate human reader performance with or without AI assistance. The device itself (BLUE 400/BLUE 400 S) is a filter accessory, not an AI-powered diagnostic tool aiming to improve reader interpretation.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done

No, a standalone algorithm performance study was not done. This device is an accessory to a surgical microscope. It enhances visualization for a human surgeon; it is not a standalone algorithm that provides diagnoses or interpretations. The software verification testing mentioned is for the device's control software, not a diagnostic algorithm.

7. The Type of Ground Truth Used

The "ground truth" for the performance testing is engineering specifications and measurements of optical, electrical, and mechanical properties. For example, excitation wavelength range is validated against the known excitation peak of PpIX, and image properties (resolution, brightness, lack of deformation) are validated against defined standards for surgical microscopes. The comparison to the predicate device also serves as a benchmark for equivalence.

8. The Sample Size for the Training Set

Not applicable. The BLUE 400 and BLUE 400 S are physical filter accessories for a surgical microscope, not an AI/machine learning device that requires a training set. The software mentioned is for the device's operation and control, not for image analysis or diagnostic inference that would necessitate a training set.

9. How the Ground Truth for the Training Set Was Established

Not applicable. As the device is not an AI/ML system requiring a training set, there is no ground truth established for such a set.

Summary

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June 28, 2024

Image /page/0/Picture/1 description: The image shows the logo of the U.S. Food and Drug Administration (FDA). On the left is the Department of Health & Human Services logo. To the right of that is the FDA logo, which consists of a blue square with the letters "FDA" in white, followed by the words "U.S. FOOD & DRUG" in blue, and the word "ADMINISTRATION" in a smaller font size below that.

Carl Zeiss Meditec AG Chaitali Gawde Senior Regulatory Affairs Specialist 5300 Central Parkway Dublin, California 94588

Re: K240215

Trade/Device Name: BLUE 400; BLUE 400 S Regulation Number: 21 CFR 882.4950 Regulation Name: Diagnostic Neurosurgical Microscope Filter Regulatory Class: Class II Product Code: QFX Dated: January 25, 2024 Received: May 31, 2024

Dear Chaitali Gawde:

We have reviewed your section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (the Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device" (https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).

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Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30, Design controls; 21 CFR 820.90, Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review. the OS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.

For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).

Sincerely, Digitally signed by Adam D. Adam D. Pierce -S Date: 2024.06.28 Pierce -S 14:17:06 -04'00'

Adam D. Pierce, Ph.D. Assistant Director DHT5A: Division of Neurosurgical, Neurointerventional and Neurodiagnostic Devices OHT5: Office of Neurological

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and Physical Medicine Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known) K240215

Device Name BLUE 400; BLUE 400 S

Indications for Use (Describe)

The ZEISS BLUE 400 and BLUE 400 S are surgical microscope accessories used in fluorescent visualization of suspected grade III and IV gliomas during neurosurgery.

Type of Use (Select one or both, as applicable)

X Prescription Use (Part 21 CFR 801 Subpart D)	Over-The-Counter Use (21 CFR 801 Subpart C)
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In accordance with 21 CFR 807.92 the 510(k) Summary for the Fluorescence Accessories is provided below.

SUBMITTER 1.

Applicant:	Carl Zeiss Meditec AGRudolf-Eber-Strasse 11D-73447OberkochenGermany
Primary Correspondent	Chaitali GawdeSenior Regulatory Affairs SpecialistCarl Zeiss Meditec, Inc.5300 Central Parkway Dublin, CA 94568(224) 300-3992 PhoneE-mail: chaitali.gawde@zeiss.com (preferred)
Secondary Correspondent	Paul SwiftHead of Regulatory and Clinical Affairs, AmericasCarl Zeiss Meditec, Inc.5300 Central Parkway Dublin, CA 94568(817) 925-8507 PhoneE-mail: paul.swift@zeiss.com
Date Prepared:	June 27, 2024

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2. DEVICE

Device Trade Name:	BLUE 400; BLUE 400 S
Classification:	21 CFR 882.4950 Diagnostic Neurosurgical Microscope Filter
Regulatory Class:	II
Product Code:	QFX

3. LEGALLY MARKETED PREDICATE DEVICE

Predicate Device Name:	BLUE 400 (K211346)
Classification:	21 CFR 882.4950 Diagnostic Neurosurgical Microscope Filter
Regulatory Class:	II
Product Code:	QFX

4. DEVICE DESCRIPTION SUMMARY

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INDICATIONS FOR USE 5.

BLUE 400 and BLUE 400 S are accessories to the surgical microscope and allow the fluorescence observation of fluorophores with an excitation peak between 400 mm and the fluorescence emission observation comprising the spectrum in a spectral band of 620 - 710 nm.

The ZEISS BLUE 400 and BLUE 400 S are surgical microscope accessories used in fluorescent visualization of suspected grade III and IV gliomas during neurosurgery.

SUBSTANTIAL EQUIVALENCE 6.

Table 1. Subject to Predicate Device Comparison Table – Indications for Use

Attribute	Subject Device	Predicate Device	Equivalence	Justification
	BLUE 400 / BLUE 400 S	BLUE 400	statement	of equivalency
	(K240215)	(K211346)
Indications forUse	BLUE 400 and BLUE 400S are accessories to thesurgical microscope andallow the fluorescenceobservation offluorophores with anexcitation peak between400 nm and 410 nm andthe fluorescence emissionobservation comprising thespectrum in a spectral bandof 620 - 710 nm.The ZEISS BLUE 400 andBLUE 400 S are surgicalmicroscope accessoriesused in fluorescentvisualization of suspectedgrade III and IV gliomasduring neurosurgery.	BLUE 400 is a surgicalmicroscope accessory filterfor viewing fluorescenceof fluorophores with anexcitation peak between400 nm and 410 nm andthe fluorescence emissionobservation comprising thespectrum in a spectral bandof 620 - 710 nm.The ZEISS BLUE 400 is asurgical microscopeaccessory used influorescent visualization ofsuspected grade III and IVgliomas duringneurosurgery.	Equivalent	Updated toinclude BLUE400 S.
PatientPopulation	Patients undergoingneurological procedureswho already have beendiagnosed with grade III &IV glioma with the aid offurther diagnosticprocedures.	Patients undergoingneurological procedures.	Equivalent	The patientpopulationremains thesame, it is onlydescribed inmore detail.
Configuration/Relationship to thedevice	BLUE 400 consists of aHW module (specificfilters).BLUE 400 S consists of aHW module (specificfilters).	BLUE 400 consists of aHW module (specificfilters).	Identical	N/A
Attribute	Subject DeviceBLUE 400 / BLUE 400 S(K240215)	Predicate DeviceBLUE 400(K211346)	Equivalencestatement	Justificationof equivalency
Manufacturer	Carl Zeiss Meditec AGGoeschwitzer Strasse 51-52D-07745 Jena Germany	Carl Zeiss Meditec AGGoeschwitzer Strasse 51-52D-07745 Jena Germany	Identical	N/A
ClassificationProduct Code	QFX	QFX	Identical	N/A
RegulationNumber	882.4950 (Diagnosticneurosurgical microscopefilter)	882.4950 (Diagnosticneurosurgical microscopefilter)	Identical	N/A
Review Panel	Neurology	Neurology	Identical	N/A
FluorescenceExcitation	BLUE 400:400 nm to 430 nm (50%edges)BLUE 400 S:398 nm to 457 nm (50%edges)	400 nm to 430 nm (50%edges)	Equivalent	Excitationwavelengthrange of PpIXis covered byboth options(400 nm to 410nm)
FluorescenceDetection	BLUE 400:> 450 nm (50% edge)BLUE 400 S:540 nm to 728 nm (50%edges)	> 450 nm (50% edge)	Equivalent	Fluorescencelight of PpIXbetween 620nm and 710nm is coveredby bothoptions.
FluorescenceAgent	5-Aminolevulinic acidhydrochloride (5-ALA HCl)Gleolan	5-Aminolevulinic acidhydrochloride (5-ALA HCl)Gleolan	Identical	N/A
CombinationDevice	No	No	Identical	N/A
VisualizationResult	Fluorescent image ofdistribution of theaccumulated protoporphyrinIX (PpIX) in malignanttissue during operation	Fluorescent image ofdistribution of theaccumulated protoporphyrinIX (PpIX) in malignanttissue during operation	Identical	N/A
Visualizationof Real TimeImages	Yes	Yes	Identical	N/A
Visualizationon Interface/Display	Yes	Yes	Identical	N/A
LightSpecifications -Type	White Light – Fluorescence	White Light – Fluorescence	Identical	N/A
Attribute	Subject DeviceBLUE 400 / BLUE 400 S(K240215)	Predicate DeviceBLUE 400(K211346)	Equivalencestatement	Justificationof equivalency
LightSpecifications -Light Source	Non-laser light source -Minimum Irradiance mustbe met (Brightness OcularImage: $\geq$ 92 nW,Measured at a workingdistance of 250 mm)	300 Watt Xenon	Equivalent	Replaced byirradiancerequired foracceptableillumination

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Table 2. Subject to Predicate Device Comparison Table – Technical Characteristics

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7. NON-CLINICAL AND/OR CLINICAL TESTS SUMMARY OF STUDIES

Sterilization and Shelf Life

The device is provided non-sterile. Shelf-Life is not applicable.

Biocompatibility

The device does not have patient-contacting materials; therefore, a biocompatibility assessment is not needed for this device.

Performance Testing - Bench

In order for BLUE 400 and BLUE 400 S to work, they must be installed onto a qualified ZEISS surgical microscope. A software license specific to BLUE 400 and BLUE 400 S must also be installed on the ZEISS microscope. Software verification testing (Documentation Level: Enhanced) has been performed in accordance with the FDA guidance document "Content of Premarket Submissions for Device Software Functions" to demonstrate that software is performing as intended. Cybersecurity concerns were addressed by providing cybersecurity documentation that included an assessment of the assets, threats, vulnerabilities, and controls in accordance with the FDA guidance document "Content of Premarket Submissions for Management of Cybersecurity in Medical Devices."

Non-clinical system testing provided an evaluation of the system relevant to each of the system specifications. The functional and system level testing showed that the system met the defined specifications. To ensure that the clinically relevant parameters for the Indications for Use of the fluorescence accessories are fulfilled, the following parameters/specifications were tested:

Test	Test Method	Results
Brightness of the fluorescenceocular image	Measurement of the image brightness of the ZEISSfluorescence target at the ocular plane at a workingdistance of 250 mm.	Passed
Irradiance	Measurement of the excitation light density in theobject plane.	Passed
Test	Test Method	Results
Spatial resolution of the ocular image	Measurement of the spatial resolution with the spatial test target in white light mode.	Passed
	@min. magnification + working distance 200mm
	@max. magnification + working distance 200mm
	Values may vary depending on different working distances.
Excitation wavelength (of the microscope)	Excitation wavelength range of PpIX is covered by both options (400 nm to 410 nm).	Passed
Excitation filter	Check of optical filter specification of excitation filter	Passed
Emission wavelength (of the microscope - ocular image)	Design review via evaluation of component specifications or measurement of the spectrum at the ocular plane.	Passed
Emission wavelength (of the microscope - video image)	Design review via evaluation of component specifications or measurement of the spectrum at the ocular plane.	Passed
Emission filter	Check of optical filter specification of emission filter	Passed
Non-mirrored video image	Visual inspection with a corresponding test target in white light mode.	Passed
Non-rotated video image	Visual inspection with a corresponding test target in white light mode.	Passed
Non-deformed video image	Visual inspection of the geometric distortions of a test target with a circle in white light mode	Passed
Centered video image	Visual inspection and measurement with a test target in white light mode.	Passed
Photometric resolution of video image	Grey value resolution test with a photometric resolution test target in white light mode.	Passed
Signal-to-noise ratio of the video image (sensitivity)	Measurement of the signal-to-noise ratio of a video image of a fluorescent target at a given signal value (pixel value).	Passed
Latency of the video image	Measurement of the video latency in white light mode.	Passed
Spatial resolution of the video image	Measurement of the spatial resolution with the spatial test target in white light mode.	Passed
Test	Test Method	Results
Spectrum of the IlluminationSource (TS1)	The irradiance spectrum (250 nm - 1020 nm, $mW/cm^2$of the illumination source was measured and verifiedwith a spectrometer. These measurements wereassessed prior to application of the excitation filtermodule.	Passed
MaximumPowerandIrradiance of the IlluminationSource (TS2)	The maximum output power and irradiance ofillumination sources were measured and verified with apower meter at the end of the microscope light guide.These measurements were assessed prior to applicationof the excitation filter module.	Passed
Irradiance Spectrum of theExcitation Light and SpectralResponse of the ExcitationFilter (TS3)	The irradiance spectrum (250 nm - 1020 nm) of theillumination light, following passage through theexcitation filter module, was measured at a workingdistance of 30 cm with a spectrometer. The edges at50% decrease of the blue excitation peak werecalculated respectively.	Passed
Maximum Excitation Powerand Power Density (TS4)	The maximum power (mW) and power density(mW/cm²) of the excitation light was measured with athermopile, at multiple different working distances andzoom settings, including the maximum and minimumzoom.The power density measurements of the subject device were compared to the predicate device.	Passed
Optical Path Loss (TS5)	To determine the overall detectable light output and thetotal losses in relation to device working distance andzoom setting, optical path loss was calculated bydividing the output signal measured at the microscopeeyepiece (without emission filter) by the illuminationsignal measured with a spectrometer at the microscopefocal plane for the same zoom setting. A reflectionstandard (white silicon remission disc) was used at aworking distance of 35 cm.	Passed
Spectrum of the Emission Filter(TS6)	The spectrum (350 nm – 1050 nm) of the emission filterwhen integrated in the surgical operating microscopewas measured with a spectroradiometer to include allthe coating and optics that affects the spectrum of the observation path. For this test the excitation filter was	Passed
Test	Test Method	Results
	removed, and a reflection standard was used at the device focal plane with different zoom settings. To compare the light that passes the observation optics and emission filter, the 50% edge of the spectrum was calculated.
Homogeneity of the ExcitationLight at the Focal Point (TS7)	The reflected signal from a white sheet of paper positioned at 30 cm working distance was imaged by the surgical operating microscope camera and the intensity profile was calculated to demonstrate the homogeneity of the excitation light.	Passed
System Sensitivity (TS8)	BLUE 400: As a diffusely reflecting and fluorescent disc the ZEISS BLUE 400 fluorescent target was used and positioned at a microscope working distance of 22.5 cm. The zoom setting was chosen to lead to the same image size of the target for all devices.The fluorescence signal in the eyepiece of the subject device was compared to the predicate device.BLUE 400 S: The fluorescence light portion of the ZEISS BLUE 400 fluorescence target, measured with BLUE 400 is scaled to and subtracted from the spectrum measured with BLUE 400 S. This results in the BLUE 400 S remission spectrum. The integral of the reconstructed fluorescence signal is divided by the integral of the reconstructed remission spectrum, corresponding to the ratio of fluorescence to emission light.	Passed
Pre-Operative Phantom Test(TS9)	This test was conducted to demonstrate that the ZEISS BLUE 400 test phantom is suitable for the pre-operative checks of a surgical microscope. The phantom has one fluorescent area and was imaged by the surgical microscope camera. The same test was repeated by observation through the microscope eyepiece.	Passed
Spectrum of the Camera Filter(TS10)	The spectrum at the camera interface was measured with a spectroradiometer to demonstrate that camera filter can block near infrared and infrared leakage of excitation light to the camera.	Passed

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Finally, special controls testing has also been performed and met the defined specifications. The following special controls testing has been conducted with and without cover glass:

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CONCLUSION 8.

Based on the similarities of the intended use/indications for use, device design, principles of operation, technological characteristics and the results of the non-clinical performance testing, the subject device, BLUE 400 and BLUE 400 S, is substantially equivalent to the legally marketed predicate device.

Regulation Number and Section

§ 882.4950 Diagnostic neurosurgical microscope filter.

(a)
Identification. A diagnostic neurosurgical microscope filter is a device intended for use during neurosurgery to visualize fluorescence and enhance visualization of tissue associated with a specific disease or condition.(b)
Classification. Class II (special controls). The special controls for this device are:(1) Non-clinical performance testing must demonstrate that the device performs as intended under anticipated conditions of use, and verify and validate filter specifications and functional characteristics, including the following:
(i) Spectrum and intensity of the illumination source;
(ii) Spectrum of the excitation and emission filter modules when integrated in the surgical operating microscope;
(iii) Excitation power and power density;
(iv) Optical path loss from illumination source to objective lens or microscope camera;
(v) Homogeneity of the excitation light at the focal plane;
(vi) Fluorescence detection sensitivity;
(vii) Verification of calibration or preoperative procedures; and
(viii) If camera-based, spectral sensitivity of the camera.
(2) Labeling must include:
(i) Identification of the filter characteristics in conjunction with a compatible surgical operating microscope, to include the following:
(A) Illumination spectrum and power density; and
(B) Excitation and emission filter spectra.
(ii) Instructions for calibration or preoperative checks to ensure device functionality prior to each use;
(iii) Instructions for use with compatible surgical operating microscopes, external light sources, and cameras;
(iv) A warning that the device should only be used with fluorophores approved for use within the specified spectral ranges; and
(v) A warning that the device is not a standalone diagnostic.