The BD Phoenix™ Automated Microbiology System is intended for the rapid identification and in vitro antimicrobial susceptibility testing of isolates from pure culture of most aerobic and facultative anaerobic Gram-negative and Gram-positive bacteria of human origin.

The BD Phoenix™ Automated Microbiology System is intended for in vitro quantitative determination of antimicrobial susceptibility by minimal inhibitory concentration (MIC) of most Gram-negative aerobic and facultative anaerobic bacteria isolates from pure culture for Enterobacteriaceae and Non-Enterobacteriaceae and most Gram-positive bacteria isolates from pure culture belonging to the genera Staphylococcus and Enterococcus.

This premarket notification is for the addition of the antimicrobial agent ampicillin at concentrations of 0.5-32 ug/mL to Gram-negative ID/AST or AST only Phoenix panels. ampicillin has been shown to be active in vitro against most strains of microorganisms listed below, as described in the FDA-approved package insert for this antimicrobial agent.

Active In Vitro and in Clinical Infections Against:

Escherichia coli Proteus mirabilis Salmonella species Shigella species

Device Description

The BD Phoenix Automated Microbiology System (Phoenix System) is an automated system for the rapid identification (ID) and antimicrobial susceptibility testing (AST) of clinically relevant bacterial isolates. The system includes the following components:

BD Phoenix instrument and software. .
BD Phoenix panels containing biochemicals for organism ID testing and antimicrobial agents . for AST determinations.
BD Phoenix ID Broth used for performing ID tests and preparing AST Broth inoculum. .
BD Phoenix AST Broth used for performing AST tests only. .
BD Phoenix AST Indicator solution added to the AST Broth to aid in bacterial growth . determination.

The Phoenix panel is a sealed and self-inoculating molded polystyrene tray with 136 micro-wells containing dried reagents. Organisms for susceptibility testing must be a pure culture and preliminarily identified as a Gram-negative or Gram-positive isolate. For each isolation equivalent to a 0.5 McFarland standard is prepared in Phoenix ID Broth.

The Phoenix AST method is a broth based microdilution test. The Phoenix System utilizes a redox indicator for the detection of organism growth in the presence of an antimicrobial agent. Measurements of changes to the indicator as well as bacterial turbidity are used in the determination of bacterial growth. Each AST panel configuration contains several antimicrobial agents with a wide range of two-fold doubling dilution concentrations.

The instrument houses the panels where they are continuously incubated at a nominal temperature of 35°C. The instrument takes readings of the panels every 20 minutes. The readings are interpreted to give an identification of the isolate, minimum inhibitory concentration (MIC) values and category interpretations, S, I, or R (sensitive, intermediate, or resistant).

AI/ML Overview

Here's an analysis of the provided text regarding the acceptance criteria and study for the BD Phoenix™ Automated Microbiology System with Ampicillin:

1. Table of Acceptance Criteria and Reported Device Performance

The acceptance criteria are not explicitly stated as numerical targets in a formal "acceptance criteria" section. Instead, the document frames "substantial equivalency" as the overarching goal, which is demonstrated by achieving high Essential Agreement (EA) and Category Agreement (CA) to a recognized reference method (NCCLS microdilution). The FDA's issuance of a substantial equivalence determination letter further validates this.

However, based on the performance table, the implicit acceptance criteria would be for EA and CA to be very high, likely exceeding 90% as seen in the reported results.

Metric	Acceptance Criteria (Implicit)	Reported Device Performance (Ampicillin)
Essential Agreement (EA)	High (e.g., >90%)	98.1% (n=838)
Category Agreement (CA)	High (e.g., >90%)	98.3% (n=838)
Intra-site Reproducibility	>90%	>90%
Inter-site Reproducibility	>95%	>95%

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

Sample Size for Test Set: 838 isolates for the Ampicillin performance evaluation. This includes "Clinical, stock and challenge isolates."
Data Provenance: The study was conducted "across multiple geographically diverse sites across the United States." The data is a mix of prospective (clinical isolates) and retrospective (stock and challenge isolates) from various sources.

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

The document does not specify the number or qualifications of experts used to establish the ground truth. It states that for clinical isolates, the Phoenix System results were compared to the NCCLS reference broth microdilution method. For challenge set isolates, they were compared to "expected results." This implies reliance on established laboratory standards and expected antimicrobial susceptibility patterns rather than individual expert adjudication of each case.

4. Adjudication Method for the Test Set

The document describes comparing the Phoenix System results to:

NCCLS reference broth microdilution method for clinical isolates.
Expected results for challenge set isolates.

This indicates a comparison against a reference standard rather than an adjudication process involving multiple human readers for each case. The "adjudication" (or determination of correctness) is against the established NCCLS method for clinical strains and pre-determined 'expected results' for challenge strains. There is no mention of physician or clinical expert adjudication on specific cases.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, If So, What Was the Effect Size of How Much Human Readers Improve with AI vs. Without AI Assistance

No, an MRMC comparative effectiveness study involving human readers and AI assistance was not conducted. This device is an automated microbiology system that performs AST and ID, not an AI-assisted diagnostic tool for human interpretation. The comparison is between the automated system and a reference lab method.

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

Yes, a standalone performance study was done. The entire evaluation is focused on the performance of the "BD Phoenix™ Automated Microbiology System" (an automated algorithm/device) against a reference standard (NCCLS broth microdilution method) without human interpretation as part of the primary outcome assessment. The system itself determines the MIC values and categorical interpretations (S, I, R).

7. The Type of Ground Truth Used

The ground truth used was:

NCCLS reference broth microdilution method: for clinical isolates. This is a recognized laboratory standard for antimicrobial susceptibility testing.
Expected results: for challenge set isolates. These are pre-determined or known susceptibility profiles for specific strains.

8. The Sample Size for the Training Set

The document does not provide any information regarding a specific training set size or methodology. The description focuses on the evaluation (test) set. Given this is an automated system developed prior to the widespread use of deep learning, it's more likely that the system's underlying rules and algorithms were developed based on extensive microbiology knowledge and earlier data, rather than a distinct "training set" in the modern machine learning sense. The "clinical, stock, and challenge" isolates mentioned appear to be solely for evaluating the performance of the established system against a reference, not for training it.

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

Since no specific "training set" is mentioned, the method for establishing its ground truth is also not described.

Summary

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K032299

CONFIDENTIAL AND PROPRIETARY

510(K) SUMMARY

SUBMITTED BY:	Becton, Dickinson and Company7 Loveton CircleSparks, MD 21152Phone: (410) 316-4206Fax: 410-316-4499
CONTACT NAME:	Bradford M. SpringManager, Regulatory Affairs
DATE PREPARED:	July 25, 2003
DEVICE TRADE NAME:	BD Phoenix™ Automated Microbiology System -Ampicillin 0.5-32 µg/mL
DEVICE COMMON NAME:	Antimicrobial susceptibility test system-short incubation
DEVICE CLASSIFICATION:	Fully Automated Short-Term Incubation Cycle AntimicrobialSusceptibility Device, 21 CFR 866.1645
PREDICATE DEVICES:	VITEK® System (PMA No. N50510) and BD Phoenix™Automated Microbiology System with Gatifloxacin (K020321May 23, 2002), Ofloxacin (K020323, April 14, 2002), andLevofloxacin (K020322, March 27, 2002).
INTENDED USE:	The BD Phoenix™ Automated Microbiology System isintended for the rapid identification and in vitro antimicrobialsusceptibility testing of isolates from pure culture of mostaerobic and facultative anaerobic Gram-negative and Gram-positive bacteria of human origin.

DEVICE DESCRIPTION:

BD Phoenix instrument and software. .
BD Phoenix panels containing biochemicals for organism ID testing and antimicrobial agents . for AST determinations.
BD Phoenix ID Broth used for performing ID tests and preparing AST Broth inoculum. .
BD Phoenix AST Broth used for performing AST tests only. .
BD Phoenix AST Indicator solution added to the AST Broth to aid in bacterial growth . determination.

Page 10

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BD PHOENIX™ Automated Microbiology System Ampicillin - GN

DEVICE COMPARISON:

The BD Phoenix™ Automated Microbiology System demonstrated substantially equivalent performance when compared with the NCCLS reference broth microdilution method. This premarket notification provides data supporting the use of the BD Phoenix™ Automated Microbiology System Gram-negative ID/AST or AST only Phoenix panels with this antimicrobial agent.

SUMMARY OF SUBSTANTIAL EQUIVALENCE TESTING:

The BD Phoenix™ Automated Microbiology System has demonstrated substantially equivalent performance when compared to the NCCLS reference broth microdilution method (AST panels prepared according to NCCLS M7). The system has been evaluated as defined in the FDA Draft guidance document, "Guidance on Review Criteria for Assessment of Antimicrobial Susceptibility Devices", March 8, 2000.

Site Reproducibility

Intra- and inter-site reproducibility of this antimicrobial agent in the BD Phoenix System was evaluated at three sites using a panel of Gram-negative isolates. Each site tested the isolates in triplicate on three different days using one lot of Gram-negative Phoenix panels containing this antimicrobial agent and associated reagents.

The results of the study demonstrate for the this antimicrobial agent there was an overall intra-site reproducibility of greater than 90% and an overall inter-site reproducibility greater than 95% for the Gram-negative isolates tested.

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Clinical Studies

Clinical, stock and challenge isolates were tested across multiple geographically diverse sites across the United States to demonstrate the performance of the Phoenix antimicrobial susceptibility test with the Gram-negative Phoenix panel format containing this antimicrobial agent. Phoenix System results for Challenge set isolates were compared to the expected results. Phoenix System results for clinical isolates were compared to the results obtained from the NCCLS reference broth microdilution method.

The performance of the Phoenix System was assessed by calculating Essential Agreement (EA) and Category Agreement (CA) to expected/reference results for all isolates tested. Essential Agreement (EA) occurs when the BD Phoenix™ Automated Microbiology System agrees exactly or within + one two-fold dilution to the reference result. Category Agreement (CA) occurs when the BD Phoenix™ Automated Microbiology System agrees with the reference method with respect to the FDA categorical interpretive criteria (susceptible, intermediate, and resistant).

Table 1 summarizes the performance for the isolates tested in this study.

Performance of BD Phoenix System for Gram-negative Organisms by Drug Table 1:

Antimicrobial	Concentration	EA (n)	EA (%)	CA (n)	CA (%)
Ampicillin	0.5-32 μg/mL	838	98.1	838	98.3

Conclusions Drawn from Substantial Equivalence Studies

The data collected from the substantial equivalence studies demonstrate that testing on the BD Phoenix™ Automated Microbiology System with this antimicrobial agent is substantially equivalent as outlined in the FDA draft guidance document, "Guidance on Review Criteria for Assessment of Antimicrobial Susceptibility Devices", March 8, 2000. Technological characteristics of this system are substantially equivalent to those used in the VITEK® system, which received approval by the FDA under PMA number N50510 and BD Phoenix™ Automated Microbiology System with Gatifloxacin (K020321, May 23, 2002), Ofloxacin (K020323, April 14, 2002), and Levofloxacin (K020322, March 27, 2002).

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DEPARTMENT OF HEALTH & HUMAN SERVICES

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SEP 2 2 2003

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

Mr. Bradford M. Spring Manager, Regulatory Affairs BD Diagnostics Systems Becton, Dickinson and Company 7 Loveton Circle Sparks, MD 21152

Re: K032299

Trade/Device Name: BD Phoenix™ Automated Microbiology System Ampicillin (0.5-32 ug/ml) Regulation Number: 21 CFR 866.1645 Regulation Name: Fully Automated Short-Term Incubation Cycle Antimicrobial Susceptibility Devices Regulatory Class: Class II Product Code: LON Dated: July 25, 2003 Received: July 25, 2003

Dear Mr. Spring:

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 (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. 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.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to such additional controls. Existing major regulations affecting your device can be found in Title 21, Code of Federal Regulations (CFR), Parts 800 to 895. In addition, FDA may publish further announcements concerning your device in the Federal Register.

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 Parts 801 and 809); and good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820).

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Page 2 -

This letter will allow you to begin marketing your device as described in your Section 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific information about the application of labeling requirements to your device, or questions on the promotion and advertising of your device, please contact the Office of In Vitro Diagnostic Device Evaluation and Safety at (301) 594-3084. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its Internet address http://www.fda.gov/cdrh/dsma/dsmamain.html.

Sincerely yours,

Steven Sutman

Steven I. Gutman, M.D., M.B.A. Director Office of In Vitro Diagnostic Device Evaluation and Safety Center for Devices and Radiological Health

Enclosure

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Page 1 of 1

510(k) Number: K032299

Device Name: BD Phoenix™ Automated Microbiology System for use with the antimicrobial agent ampicillin (0.5-32 µg/mL) - Gram-negative ID/AST or AST only Phoenix panels.

Indications for Use:

Active In Vitro and in Clinical Infections Against:

Escherichia coli Proteus mirabilis Salmonella species Shigella species

(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODE)

Sa attm 9/16/03
Division Sign-Off

Division Sign-Off

Office of In Vitro Diagnostic Device Evaluation and Safety

Image /page/5/Picture/15 description: The image shows the words "Prescription Use" in bold font, followed by the text "(Per 21 CFR 801.109)" in a smaller font. There is a check mark to the right of the text. The check mark is pointing down towards the text.

Ko 32299 510(k).

Over-the-Counter Use

BD Diagnostic Systems Becton, Dickinson and Company

Regulation Number and Section

§ 866.1645 Fully automated short-term incubation cycle antimicrobial susceptibility system.

(a)
Identification. A fully automated short-term incubation cycle antimicrobial susceptibility system is a device that incorporates concentrations of antimicrobial agents into a system for the purpose of determining in vitro susceptibility of bacterial pathogens isolated from clinical specimens. Test results obtained from short-term (less than 16 hours) incubation are used to determine the antimicrobial agent of choice to treat bacterial diseases.(b)
Classification. Class II (special controls). The special control for this device is FDA's guidance document entitled “Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA.”