21 CFR § 868.1170 - Indwelling blood hydrogen ion concentration (pH) analyzer.
---
identifier: "/us/cfr/t21/s868.1170"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 868.1170 - Indwelling blood hydrogen ion concentration (pH) analyzer."
title_number: 21
title_name: "Food and Drugs"
section_number: "868.1170"
section_name: "Indwelling blood hydrogen ion concentration (pH) analyzer."
chapter_name: "FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES"
subchapter_number: "H"
subchapter_name: "MEDICAL DEVICES"
part_number: "868"
part_name: "ANESTHESIOLOGY 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: "47 FR 31142, July 16, 1982, unless otherwise noted."
cfr_part: "868"
---
# 868.1170 Indwelling blood hydrogen ion concentration (pH) analyzer.
(a) *Identification.* An indwelling blood hydrogen ion concentration (pH) analyzer is a device that consists of a catheter-tip pH electrode and that is used to measure, in vivo, the hydrogen ion concentration (pH) in blood to aid in determining the patient's acid-base balance.
(b) *Classification.* Class II (special controls). The special control for this device is FDA's “Class II Special Controls Guidance Document: Indwelling Blood Gas Analyzers; Final Guidance for Industry and FDA.”
[47 FR 31142, July 16, 1982, as amended at 52 FR 17735, May 11, 1987; 66 FR 57368, Nov. 15, 2001]