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. 86 FR 73973 , Dec. 29, 2021