21 CFR § 882.4950 - Diagnostic neurosurgical microscope filter.

---
identifier: "/us/cfr/t21/s882.4950"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 882.4950 - Diagnostic neurosurgical microscope filter."
title_number: 21
title_name: "Food and Drugs"
section_number: "882.4950"
section_name: "Diagnostic neurosurgical microscope filter."
chapter_name: "FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES"
subchapter_number: "H"
subchapter_name: "MEDICAL DEVICES"
part_number: "882"
part_name: "NEUROLOGICAL DEVICES"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "21 U.S.C. 351, 360, 360c, 360e, 360j, 360 371."
regulatory_source: "44 FR 51730, Sept. 4, 1979, unless otherwise noted."
cfr_part: "882"
---


# 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]