(354 days)
No
The device uses "method-specific algorithms" to process results, but there is no mention of AI models, machine learning, or deep learning, which are typically indicative of an AI model's presence. The term "algorithms" here likely refers to traditional programming logic.
No
This device is an in vitro diagnostic test designed to detect influenza A and B viral antigens, which aids in diagnosis. It does not provide any therapeutic treatment.
Yes
The "Intended Use / Indications for Use" section explicitly states that "The test is intended for use with the Acucy or Acucy 2 Reader as an aid in the diagnosis of influenza A and B viral infections."
No
The device is not a software-only medical device. While it utilizes the Acucy 2 Reader, which runs "method-specific algorithms" to process results, the core of the device is a "rapid chromatographic immunoassay" involving physical test cassettes, patient samples, chemical reactions, and physical detection of antigens. The software functions primarily as a reader and interpreter of optical signals from a physical test, not as a standalone diagnostic tool. The device description details a complex physical process for viral antigen detection.
Yes.
The device is an immunoassay for the qualitative detection and differentiation of influenza A and B viral antigens directly from patient samples, intended as an aid in diagnosis. This clearly falls under the definition of an In Vitro Diagnostic (IVD) device, as it is used to examine specimens derived from the human body for the purpose of providing information for diagnosis, monitoring, or screening.
N/A
Intended Use / Indications for Use
The Acucy Influenza A&B Test is a rapid chromatographic immunoassay for the qualitative detection and differentiation of influenza A and B viral nucleoprotein antigens directly from anterior nasal and nasopharyngeal swabs from patients with signs and symptoms of respiratory infection. The test is intended for use with the Acucy or Acucy 2 Reader as an aid in the diagnosis of influenza A and B viral infections. The test is not intended for the detection of influenza C viruses. Negative test results are presumptive and should be confirmed by viral culture or an FDA-cleared influenza A and B molecular assay. Negative test results do not preclude influenza viral infection and should not be used as the sole basis for treatment or other patient management decisions.
Performance characteristics for influenza A were established during the 2017-2018 influenza season when influenza A/H3N2 and A/H1N1pdm09 were the predominant influenza A viruses in circulation. When other influenza A viruses are emerging, performance characteristics may vary.
If an infection with a novel influenza A virus is suspected based on current clinical and epidemiological screening criteria recommended by public health authorities, specimens should be collected with appropriate infection control precautions for novel virulent influenza viruses and sent to state or local health department for testing. Viral culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture specimens.
Product codes
PSZ
Device Description
The Acucy Influenza A&B Test allows for the differential detection of influenza A and influenza B antigens, when used with the Acucy 2 Reader. The patient sample is placed in the Extraction Buffer vial, during which time the virus particles in the sample are disrupted, exposing internal viral nucleoproteins. After disruption, the sample is dispensed into the Test Cassette sample well. From the sample well, the sample migrates along the membrane surface. If influenza A or B viral antigens are present, they will form a complex with mouse monoclonal antibodies to influenza A and/or B nucleoproteins conjugated to colloidal gold. The complex will then be bound by a rat anti-influenza A and/or mouse anti-influenza B antibody coated on the nitrocellulose membrane.
Depending upon the operator's choice, the Test Cassette is either placed inside the Acucy 2 Reader for automatically timed development mode (WALK AWAY Mode) or placed on the counter or bench top for a manually timed development and then placed into Acucy 2 Reader to be scanned (READ NOW Mode).
The Acucy 2 Reader will scan the Test Cassette and measure the absorbance intensity by processing the results using method-specific algorithms. The Acucy 2 Reader will display the test results POS (+), NEG (-), or INVALID on the screen. The results can also be automatically printed on the optional Printer if this option is selected.
Mentions image processing
Not Found
Mentions AI, DNN, or ML
Not Found
Input Imaging Modality
Not Found
Anatomical Site
anterior nasal and nasopharyngeal swabs
Indicated Patient Age Range
Not Found
Intended User / Care Setting
Not Found
Description of the training set, sample size, data source, and annotation protocol
Not Found
Description of the test set, sample size, data source, and annotation protocol
A panel of swabs including negative (no virus), high negative (below the limit of detection), low positive (at or near the limit of detection) and moderate positive (at or near 2x the limit of detection) for influenza A and B were coded, randomized, and masked to the operators.
Summary of Performance Studies
Precision Study Summary:
Type: Analytical Performance.
Purpose: To evaluate the consistency of performance of the Acucy 2 reader when using the Acucy Influenza A&B Test as part of the Acucy 2 System.
Sample Size: Within Laboratory Repeatability Study: 80 replicates per panel member. Instrument to Instrument Precision Study: 75 replicates per panel member on 3 different instruments.
Key Results:
Within Laboratory Repeatability Study: For all Flu A MP, Flu A LP, Flu A HN, Flu B MP, Flu B LP, Flu AB HN, and Negative samples, Agreement was 100% (80/80 count) with 95% CI of 95.4% – 100%.
Instrument to Instrument Precision Study: All results were as expected with 100% agreement for positive controls and 0% positive for negative controls across all 3 readers and 5 days.
Test Mode Equivalency Study:
Type: Analytical Performance.
Purpose: To qualify the two available test modes of the Acucy 2 System (READ NOW and WALK AWAY) and confirm that they function equivalently.
Sample Size: 20 replicates each of contrived positive Flu A and Flu B at 2x LoD and 20 Flu A and Flu B negative samples.
Key Results: All tests showed the expected results, positives read as positives in both modes and negatives read as negatives whether in the READ NOW or WALK AWAY mode. The two available test modes function equivalently.
Limit of Detection (LoD):
Type: Analytical Performance.
Purpose: To compare the analytical sensitivity of the Acucy and Acucy 2 readers side by side and establish the LoD.
Sample Size: Range finding experiment: 5 replicates per concentration. Confirmation testing: 20 replicates per concentration.
Key Results: The LoD for all strains tested on both lots of devices were identical whether tested using Acucy or Acucy 2, confirming that the performance of the Acucy 2 is equivalent to the Acucy.
Analytical Cutoff Study:
Type: Analytical Performance.
Purpose: To establish the Limit of Blank (LoB) of the Acucy Influenza A&B Assay on the Acucy 2 System.
Sample Size: 60 replicates of a blank sample per lot (two lots used).
Key Results: All blank samples showed 0 mABS. The analytical cut-off for Acucy 2 has been set to match the previously established cut-off of 6.4 and 5.4 mABS for Flu A Line and Flu B Line respectively.
Cross Contamination Study:
Type: Analytical Performance.
Purpose: To evaluate if there is any target carryover between test cassettes leading to cross-contamination between samples when testing the Acucy Influenza A&B test on the Acucy 2 system.
Sample Size: 120 samples (60 negatives, 30 Flu A high positive, 30 Flu B high positive).
Key Results: All tests showed expected results, positives read as positives and negatives read as negatives, indicating no cross-contamination.
Method Comparison - Acucy Reader vs. Acucy 2 Reader:
Type: Comparative Study.
Purpose: To establish performance equivalence between the Acucy and Acucy 2 Readers.
Sample Size: 30 PCR confirmed Flu A positive clinical samples, 30 PCR confirmed Flu B positive clinical samples, and 30 Flu A and Flu B negative clinical samples.
Key Results:
Influenza A: PPA: 100%, NPA: 98.3%. (One confirmed Flu B positive sample generated a double positive result with Acucy 2).
Influenza B: PPA: 100%, NPA: 100%.
CLIA Waiver Studies:
Flex Studies:
Type: Usability Study.
Purpose: To characterize operator workflow and usability risks identified with use of the Acucy Influenza A&B test on the Acucy 2 System by simulating conditions where the test was performed outside the intended use instructions and environment.
Sample Size: 5 replicates for every flex condition.
Key Results: All hazards and sources of potential error have been controlled to reasonably acceptable levels through design features and appropriate labelling mitigations.
Reproducibility:
Type: Reproducibility Study.
Purpose: To evaluate the reproducibility of the Acucy Influenza A&B Test.
Sample Size: Not explicitly stated for each panel member, but includes results from multiple sites and operators.
Key Results: The Acucy Influenza A&B Test produces reproducible results when tested by multiple intended users, at multiple sites, over multiple days for both the Acucy Reader and Acucy 2 Reader.
Acucy Influenza A, External Multi-Site Reproducibility Study Results:
Influenza A (H3N2) High Negative: Total 98.9% (89/90)
Influenza A (H3N2) Low Positive: Total 100% (90/90)
Influenza A (H3N2) Moderate Positive: Total 100% (90/90)
Negative: Total 100% (90/90)
Acucy Influenza B, External Multi-Site Reproducibility Study Results:
Influenza B High Negative: Total 100% (90/90)
Influenza B Low Positive: Total 100% (90/90)
Influenza B Moderate Positive: Total 98.9% (89/90)
Negative: Total 100% (90/90)
Acucy 2 Influenza A, External Multi-Site Reproducibility Study Results:
Influenza A High Negative: Total 100% (90/90)
Influenza A Low Positive: Total 100% (90/90)
Influenza A Moderate Positive: Total 100% (90/90)
Acucy 2 Influenza B, External Multi-Site Reproducibility Study Results:
Influenza B High Negative: Total 100% (90/90)
Influenza B Low Positive: Total 100% (90/90)
Influenza B Moderate Positive: Total 100% (90/90)
Acucy 2 Negative, External Multi-Site Reproducibility Study Results:
Influenza A & B Negative: Total 100% (90/90)
Key Metrics
Precision Study:
Agreement: 100% for all samples in Within Laboratory Repeatability Study.
Method Comparison - Acucy Reader vs. Acucy 2 Reader:
Influenza A: PPA: 100%, NPA: 98.3%
Influenza B: PPA: 100%, NPA: 100%
Reproducibility Studies (Acucy Reader and Acucy 2 Reader):
Agreement ranges from 98.9% to 100% across different samples and sites.
Predicate Device(s)
Reference Device(s)
Not Found
Predetermined Change Control Plan (PCCP) - All Relevant Information
Not Found
§ 866.3328 Influenza virus antigen detection test system.
(a)
Identification. An influenza virus antigen detection test system is a device intended for the qualitative detection of influenza viral antigens directly from clinical specimens in patients with signs and symptoms of respiratory infection. The test aids in the diagnosis of influenza infection and provides epidemiological information on influenza. Due to the propensity of the virus to mutate, new strains emerge over time which may potentially affect the performance of these devices. Because influenza is highly contagious and may lead to an acute respiratory tract infection causing severe illness and even death, the accuracy of these devices has serious public health implications.(b)
Classification. Class II (special controls). The special controls for this device are:(1) The device's sensitivity and specificity performance characteristics or positive percent agreement and negative percent agreement, for each specimen type claimed in the intended use of the device, must meet one of the following two minimum clinical performance criteria:
(i) For devices evaluated as compared to an FDA-cleared nucleic acid based-test or other currently appropriate and FDA accepted comparator method other than correctly performed viral culture method:
(A) The positive percent agreement estimate for the device when testing for influenza A and influenza B must be at the point estimate of at least 80 percent with a lower bound of the 95 percent confidence interval that is greater than or equal to 70 percent.
(B) The negative percent agreement estimate for the device when testing for influenza A and influenza B must be at the point estimate of at least 95 percent with a lower bound of the 95 percent confidence interval that is greater than or equal to 90 percent.
(ii) For devices evaluated as compared to correctly performed viral culture method as the comparator method:
(A) The sensitivity estimate for the device when testing for influenza A must be at the point estimate of at least 90 percent with a lower bound of the 95 percent confidence interval that is greater than or equal to 80 percent. The sensitivity estimate for the device when testing for influenza B must be at the point estimate of at least 80 percent with a lower bound of the 95 percent confidence interval that is greater than or equal to 70 percent.
(B) The specificity estimate for the device when testing for influenza A and influenza B must be at the point estimate of at least 95 percent with a lower bound of the 95 percent confidence interval that is greater than or equal to 90 percent.
(2) When performing testing to demonstrate the device meets the requirements in paragraph (b)(1) of this section, a currently appropriate and FDA accepted comparator method must be used to establish assay performance in clinical studies.
(3) Annual analytical reactivity testing of the device must be performed with contemporary influenza strains. This annual analytical reactivity testing must meet the following criteria:
(i) The appropriate strains to be tested will be identified by FDA in consultation with the Centers for Disease Control and Prevention (CDC) and sourced from CDC or an FDA-designated source. If the annual strains are not available from CDC, FDA will identify an alternative source for obtaining the requisite strains.
(ii) The testing must be conducted according to a standardized protocol considered and determined by FDA to be acceptable and appropriate.
(iii) By July 31 of each calendar year, the results of the last 3 years of annual analytical reactivity testing must be included as part of the device's labeling. If a device has not been on the market long enough for 3 years of annual analytical reactivity testing to have been conducted since the device received marketing authorization from FDA, then the results of every annual analytical reactivity testing since the device received marketing authorization from FDA must be included. The results must be presented as part of the device's labeling in a tabular format, which includes the detailed information for each virus tested as described in the certificate of authentication, either by:
(A) Placing the results directly in the device's § 809.10(b) of this chapter compliant labeling that physically accompanies the device in a separate section of the labeling where the analytical reactivity testing data can be found; or
(B) In the device's label or in other labeling that physically accompanies the device, prominently providing a hyperlink to the manufacturer's public Web site where the analytical reactivity testing data can be found. The manufacturer's home page, as well as the primary part of the manufacturer's Web site that discusses the device, must provide a prominently placed hyperlink to the Web page containing this information and must allow unrestricted viewing access.
(4) If one of the actions listed at section 564(b)(1)(A)-(D) of the Federal Food, Drug, and Cosmetic Act occurs with respect to an influenza viral strain, or if the Secretary of Health and Human Services (HHS) determines, under section 319(a) of the Public Health Service Act, that a disease or disorder presents a public health emergency, or that a public health emergency otherwise exists, with respect to an influenza viral strain:
(i) Within 30 days from the date that FDA notifies manufacturers that characterized viral samples are available for test evaluation, the manufacturer must have testing performed on the device with those viral samples in accordance with a standardized protocol considered and determined by FDA to be acceptable and appropriate. The procedure and location of testing may depend on the nature of the emerging virus.
(ii) Within 60 days from the date that FDA notifies manufacturers that characterized viral samples are available for test evaluation and continuing until 3 years from that date, the results of the influenza emergency analytical reactivity testing, including the detailed information for the virus tested as described in the certificate of authentication, must be included as part of the device's labeling in a tabular format, either by:
(A) Placing the results directly in the device's § 809.10(b) of this chapter compliant labeling that physically accompanies the device in a separate section of the labeling where analytical reactivity testing data can be found, but separate from the annual analytical reactivity testing results; or
(B) In a section of the device's label or in other labeling that physically accompanies the device, prominently providing a hyperlink to the manufacturer's public Web site where the analytical reactivity testing data can be found. The manufacturer's home page, as well as the primary part of the manufacturer's Web site that discusses the device, must provide a prominently placed hyperlink to the Web page containing this information and must allow unrestricted viewing access.
FDA 510(k) Clearance Letter - Acucy Influenza A&B Test with the Acucy 2 System
Page 1
U.S. Food & Drug Administration
10903 New Hampshire Avenue
Silver Spring, MD 20993
www.fda.gov
Doc ID # 04017.07.05
April 18, 2025
Sekisui Diagnostics, LLC
Jason Bilobram
Principal Regulatory Affairs Specialist
6659 Top Gun Street
San Diego, California 92121
Re: K241188
Trade/Device Name: Acucy Influenza A&B Test with the Acucy 2 System
Regulation Number: 21 CFR 866.3328
Regulation Name: Influenza Virus Antigen Detection Test System
Regulatory Class: Class II
Product Code: PSZ
Dated: April 27, 2024
Received: April 29, 2024
Dear Jason Bilobram:
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.
Page 2
K241188 - Jason Biolobram Page 2
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).
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 QS 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 and Part 809); medical device reporting (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-reporting-combination-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.
All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rule"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/unique-device-identification-system-udi-system.
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-devices/medical-device-safety/medical-device-reporting-mdr-how-report-medical-device-problems.
For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medical-devices/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-devices/device-advice-comprehensive-regulatory-
Page 3
K241188 - Jason Biolobram Page 3
assistance/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,
Silke Schlottmann -S (Digitally signed by Silke Schlottmann -S Date: 2025.04.18 11:10:32 -04'00')
Silke Schlottmann, Ph.D.
Deputy Assistant Director
Division of Microbiology Devices
OHT7: Office of In Vitro Diagnostics
Office of Product Evaluation and Quality
Center for Devices and Radiological Health
Enclosure
Page 4
FORM FDA 3881 (6/20) Page 1 of 1 PSC Publishing Services (301) 443-6740 EF
DEPARTMENT OF HEALTH AND HUMAN SERVICES
Food and Drug Administration
Indications for Use
Form Approved: OMB No. 0910-0120
Expiration Date: 06/30/2023
See PRA Statement below.
510(k) Number (if known): K241188
Device Name: Acucy Influenza A&B Test with the Acucy 2 System
Indications for Use (Describe)
The Acucy Influenza A&B Test is a rapid chromatographic immunoassay for the qualitative detection and differentiation of influenza A and B viral nucleoprotein antigens directly from anterior nasal and nasopharyngeal swabs from patients with signs and symptoms of respiratory infection. The test is intended for use with the Acucy or Acucy 2 Reader as an aid in the diagnosis of influenza A and B viral infections. The test is not intended for the detection of influenza C viruses. Negative test results are presumptive and should be confirmed by viral culture or an FDA-cleared influenza A and B molecular assay. Negative test results do not preclude influenza viral infection and should not be used as the sole basis for treatment or other patient management decisions.
Performance characteristics for influenza A were established during the 2017-2018 influenza season when influenza A/H3N2 and A/H1N1pdm09 were the predominant influenza A viruses in circulation. When other influenza A viruses are emerging, performance characteristics may vary.
If infection with a novel influenza A virus is suspected based on current clinical and epidemiological screening criteria recommended by public health authorities, specimens should be collected with appropriate infection control precautions for novel virulent influenza viruses and sent to state or local health department for testing. Viral culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture specimens.
Type of Use (Select one or both, as applicable)
☒ Prescription Use (Part 21 CFR 801 Subpart D) ☐ Over-The-Counter Use (21 CFR 801 Subpart C)
CONTINUE ON A SEPARATE PAGE IF NEEDED.
This section applies only to requirements of the Paperwork Reduction Act of 1995.
DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.
The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to:
Department of Health and Human Services
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"An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number."
Page 5
510(k) Summary (K231187)
Acucy Influenza A&B Test with the Acucy 2 System
Page 1 of 18
As required by 21 CFR Section 807.92(c).
Submitted by: Sekisui Diagnostics
6659 Top Gun Street
San Diego, CA 92121
Phone: (858) 777-2600
Contact: Jason Bilobram
Date of Preparation: April 17, 2025
Trade name: Acucy Influenza A&B Test with the Acucy 2 System
Common name: Acucy 2 Reader with Influenza A/B
Type of Test: Rapid chromatographic immunoassay for the qualitative detection of influenza A and B nucleoprotein antigens
Regulation number: 21 CFR 866.3328
Classification Name: Influenza virus antigen detection test system
Product code: PSZ
Classification: Class II
Advisory Panel: Microbiology (83)
Prescription Use: Yes
Predicate Device Assay: Acucy Influenza A&B Test with the Acucy System (K182001)
Page 6
510(k) Summary (K231187)
Acucy Influenza A&B Test with the Acucy 2 System
Page 2 of 18
1. Device Description
The Acucy Influenza A&B Test allows for the differential detection of influenza A and influenza B antigens, when used with the Acucy 2 Reader. The patient sample is placed in the Extraction Buffer vial, during which time the virus particles in the sample are disrupted, exposing internal viral nucleoproteins. After disruption, the sample is dispensed into the Test Cassette sample well. From the sample well, the sample migrates along the membrane surface. If influenza A or B viral antigens are present, they will form a complex with mouse monoclonal antibodies to influenza A and/or B nucleoproteins conjugated to colloidal gold. The complex will then be bound by a rat anti-influenza A and/or mouse anti-influenza B antibody coated on the nitrocellulose membrane.
Depending upon the operator's choice, the Test Cassette is either placed inside the Acucy 2 Reader for automatically timed development mode (WALK AWAY Mode) or placed on the counter or bench top for a manually timed development and then placed into Acucy 2 Reader to be scanned (READ NOW Mode).
The Acucy 2 Reader will scan the Test Cassette and measure the absorbance intensity by processing the results using method-specific algorithms. The Acucy 2 Reader will display the test results POS (+), NEG (-), or INVALID on the screen. The results can also be automatically printed on the optional Printer if this option is selected.
2. Device Intended Use
The Acucy Influenza A&B Test is a rapid chromatographic immunoassay for the qualitative detection and differentiation of influenza A and B viral nucleoprotein antigens directly from anterior nasal and nasopharyngeal swabs from patients with signs and symptoms of respiratory infection. The test is intended for use with the Acucy or Acucy 2 Reader as an aid in the diagnosis of influenza A and B viral infections. The test is not intended for the detection of influenza C viruses. Negative test results are presumptive and should be confirmed by viral culture or an FDA-cleared influenza A and B molecular assay. Negative test results do not preclude influenza viral infection and should not be used as the sole basis for treatment or other patient management decisions.
Page 7
510(k) Summary (K231187)
Acucy Influenza A&B Test with the Acucy 2 System
Page 3 of 18
Performance characteristics for influenza A were established during the 2017-2018 influenza season when influenza A/H3N2 and A/H1N1pdm09 were the predominant influenza A viruses in circulation. When other influenza A viruses are emerging, performance characteristics may vary.
If an infection with a novel influenza A virus is suspected based on current clinical and epidemiological screening criteria recommended by public health authorities, specimens should be collected with appropriate infection control precautions for novel virulent influenza viruses and sent to state or local health department for testing. Viral culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture specimens.
Acucy Influenza A&B Kit Contents:
The Acucy Influenza A&B Test Kit contains all the materials needed to run a test, except for the Acucy 2 System, which is provided separately. The Acucy Influenza Test Kit contains the following components:
- 25 Test Cassettes: individually foil pouched with desiccant.
- 25 Sterile Anterior Nasal Swabs
- 25 Extraction Buffer vials each containing: 0.4 mL phosphate buffered salt solution (with 0.09% sodium azide)
- 25 Extraction Vial Dropper Tips
- 1 Influenza A+/B- Control Swab (Formalin inactivated influenza A containing 0.05% sodium azide)
- 1 Influenza A-/B+ Control Swab (Formalin inactivated influenza B containing 0.05% sodium azide)
- 2 Instructions for Use (IFU): 1 Acucy Reader, 1 Acucy 2 Reader
- 2 Quick Reference Guide: 1 Acucy Reader, 1 Acucy 2 Reader
- 2 External Quality Control (QC) Quick Reference Guide: 1 Acucy Reader, 1 Acucy 2 Reader
- 1 Workstation
- Note: Two extra test cassettes and reagents have been included in the kit for external quality control testing.
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510(k) Summary (K231187)
Acucy Influenza A&B Test with the Acucy 2 System
Page 4 of 18
3. Substantial Equivalence
| Attribute | Subject Device | Predicate Device |
|---|---|---|
| Acucy 2 Reader with Influenza A/B (K241188) | Acucy Reader with Influenza A/B (K182001) | |
| Intended Use | The Acucy Influenza A&B Test is a rapid chromatographic immunoassay for the qualitative detection and differentiation of influenza A and B viral nucleoprotein antigens directly from anterior nasal and nasopharyngeal swabs from patients with signs and symptoms of respiratory infection. The test is intended for use with the Acucy or Acucy 2 Reader as an aid in the diagnosis of influenza A and B viral infections. The test is not intended for the detection of influenza C viruses. Negative test results are presumptive and should be confirmed by viral culture or an FDA-cleared influenza A and B molecular assay. Negative test results do not preclude influenza viral infection and should not be used as the sole basis for treatment or other patient management decisions. |
Performance characteristics for influenza A were established during the 2017-2018 influenza season when influenza A/H3N2 and A/H1N1pdm09 were the predominant influenza A viruses in circulation. When other influenza A viruses are emerging, performance characteristics may vary.
If infection with a novel influenza A virus is suspected based on current clinical and epidemiological screening criteria recommended by public health authorities, specimens should be collected with appropriate infection control precautions for novel virulent influenza viruses and sent to state or local health department for testing. | The Acucy® Influenza A&B Test for the rapid qualitative detection of influenza A&B is composed of a rapid chromatographic immunoassay for the direct and qualitative detection of influenza A and B viral nucleoprotein antigens from nasal and nasopharyngeal swabs of symptomatic patients that is automatically analyzed on the Acucy® Reader. The Acucy Influenza A&B Test is a differentiated test, such that influenza A viral antigens can be distinguished from influenza B viral antigens from a single processed sample using a single Test Cassette. The test is intended for use with the Acucy® System as an aid in the diagnosis of influenza A and B viral infections. The test is not intended for the detection of influenza C viruses. Negative test results are presumptive and should be confirmed by viral culture or an approved influenza A and B molecular assay. Negative test results do not preclude influenza viral infection and should not be used as the sole basis for treatment or other patient management decisions.
Performance characteristics for influenza A were established during the 2017-2018 influenza season when influenza A/H3N2 and A/H1N1pdm09 were the predominant influenza A viruses in circulation. When other influenza A viruses are emerging, performance characteristics may vary.
If infection with a novel influenza A virus is suspected based on current clinical and epidemiological screening criteria recommended by public health |
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| Attribute | Subject Device | Predicate Device |
|---|---|---|
| Acucy 2 Reader with Influenza A/B (K241188) | Acucy Reader with Influenza A/B (K182001) | |
| Viral culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture specimens. | authorities, specimens should be collected with appropriate infection control precautions for novel virulent influenza viruses and sent to state or local health department for testing. Viral culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture specimens. |
For near-patient, laboratory professional and healthcare professional in vitro diagnostic use only. |
| Regulation | Same | 21 CFR 866.3328 |
| Product Code | Same | PSZ |
| Device Class | Same | Device Class II |
| Technology/Detection | Same | The Acucy Influenza A&B Test allows for the differential detection of influenza A and influenza B antigens, when used with the Acucy Reader. The Acucy Reader will scan the test cassette and measure the absorbance intensity by processing the results using method-specific algorithms. |
| Assay Targets | Same | Influenza A, Influenza B |
| Specimen Type | Same | Nasal Swab (NS)
Nasopharyngeal Swab (NPS) |
| Transport Media | Same | Viral Transport Media (VTM) |
| Test Format | Same | Lateral Flow, Cassette |
| Automation | Same | Detection and Results Interpretation |
| Assay Results | Same | Qualitative |
| Internal Control | Same | • Scan prevents use of expired or used cassettes
• Scanning control for adequate flow
• Scan prevents improper cassette insertions |
| Instrument Systems | Acucy 2 Instrument System | Acucy Instrument System |
| Time to Result | Same | 15 minutes Read Time |
The following performance data (analytical and clinical) were provided in support of the substantial equivalence determination.
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4. Performance Studies
4.1 Analytical Performance
Precision Study Summary
The purpose of this study was to evaluate the consistency of performance of the Acucy 2 reader when using the Acucy Influenza A&B Test as part of the Acucy 2 System. The studies were designed to assess Within-Laboratory Repeatability over multiple days and Instrument-to-Instrument Variability.
On each day of testing, contrived positive samples at 0.95x (Low Positive), 2x LoD (Moderate positive), and 0.05x LoD (High negative) were prepared. Contrived swabs were prepared by adding 50µL of sample to head of swab. Negative samples were prepared by adding 50µL of sample to the head of swab. Swabs were dried for 1 minute. All further testing is performed as per Acucy Influenza A&B Instructions for Use (IFU, PN 3248).
Table 1: Expected results for sample panel tested in precision studies
| Panel member | Target Concentration | Target Positive Detection Rate |
|---|---|---|
| Negative (N) | 0x LoD | 0% |
| High Negative (HN) | Flu A or Flu B 0.05x LoD | 0-5% |
| Low Positive (L) | Flu A or Flu B 0.95x LoD | ≥95% |
| Moderate Positive (M) | Flu A or Flu B 2x LoD | 100% |
Within Laboratory Repeatability Study
The precision panel tested comprised of a total of 7 panel members one (1) negative sample, two (2) High Negative samples (0.05x LoD – one each for Flu A and Flu B), two (2) low positive samples (0.95x LoD – one each for Flu A and Flu B), and two (2) moderate positive samples (2x LoD – one each for Flu A and Flu B). All testing was done with Influenza A Michigan and Influenza B Colorado. In order to evaluate the repeatability of the testing within a lab, one (1) lot of Acucy Influenza A&B test was tested by one (1) operator using the seven-member
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precision panel twice per day for twenty days (n=2). Over the course of 20 days, 80 replicates were run per panel member (1 operator x 20 days x 2 runs x 2 replicates).
Table 2a: Acucy, Within Laboratory Repeatability Study Results
| Sample | Count | Agreement | 95% CI |
|---|---|---|---|
| Flu A MP | 80/80 | 100% | 95.4% – 100% |
| Flu A LP | 80/80 | 100% | 95.4% – 100% |
| Flu A HN | 80/80 | 100% | 95.4% – 100% |
| Flu B MP | 80/80 | 100% | 95.4% – 100% |
| Flu B LP | 80/80 | 100% | 95.4% – 100% |
| Flu AB HN | 80/80 | 100% | 95.4% – 100% |
| Negative | 80/80 | 100% | 95.4% – 100% |
Table 2b: Acucy 2, Within Laboratory Repeatability Study Results
| Sample | Count | Agreement | 95% CI |
|---|---|---|---|
| Flu A MP | 80/80 | 100% | 95.4% – 100% |
| Flu A LP | 80/80 | 100% | 95.4% – 100% |
| Flu A HN | 80/80 | 100% | 95.4% – 100% |
| Flu B MP | 80/80 | 100% | 95.4% – 100% |
| Flu B LP | 80/80 | 100% | 95.4% – 100% |
| Flu AB HN | 80/80 | 100% | 95.4% – 100% |
| Negative | 80/80 | 100% | 95.4% – 100% |
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Instrument to Instrument Precision Study
To evaluate the instrument-to-instrument precision, one (1) lot of Acucy Influenza A&B was tested by one (1) operator. The seven-member precision panel was tested in five (5) replicates each on three (3) different Acucy 2 readers on five days as described above. Over the course of 5 days, 25 replicates were obtained per panel member per instrument (1 operator x 5 replicates x 5 days). In total there are 75 replicates per panel member on 3 different instruments (1 operator x 5 replicates x 3 instruments x 5 days). All the results were as expected on all days as per the acceptance criteria listed below. The acceptance criteria for the seven (7) member panel and the results are shown in Table 3.
Table 3: Instrument to Instrument Precision Study
| Test Organism | Day | Flu A | Flu B | N/A | ||||
|---|---|---|---|---|---|---|---|---|
| Sample Type | M | L | HN | M | L | HN | N | |
| Concentration Tested (x LoD) | 2 | 0.95 | 0.05 | 2 | 0.95 | 0.05 | Neg | |
| Reader # 100015 | ||||||||
| 1 | 5/5 | 5/5 | 0/5 | 5/5 | 5/5 | 0/5 | 0/5 | |
| 2 | 5/5 | 5/5 | 0/5 | 5/5 | 5/5 | 0/5 | 0/5 | |
| 3 | 5/5 | 5/5 | 0/5 | 5/5 | 5/5 | 0/5 | 0/5 | |
| 4 | 5/5 | 5/5 | 0/5 | 5/5 | 5/5 | 0/5 | 0/5 | |
| 5 | 5/5 | 5/5 | 0/5 | 5/5 | 5/5 | 0/5 | 0/5 | |
| Reader # 100017 | ||||||||
| 1 | 5/5 | 5/5 | 0/5 | 5/5 | 5/5 | 0/5 | 0/5 | |
| 2 | 5/5 | 5/5 | 0/5 | 5/5 | 5/5 | 0/5 | 0/5 | |
| 3 | 5/5 | 5/5 | 0/5 | 5/5 | 5/5 | 0/5 | 0/5 | |
| 4 | 5/5 | 5/5 | 0/5 | 5/5 | 5/5 | 0/5 | 0/5 | |
| 5 | 5/5 | 5/5 | 0/5 | 5/5 | 5/5 | 0/5 | 0/5 | |
| Reader # 100022 | ||||||||
| 1 | 5/5 | 5/5 | 0/5 | 5/5 | 5/5 | 0/5 | 0/5 | |
| 2 | 5/5 | 5/5 | 0/5 | 5/5 | 5/5 | 0/5 | 0/5 | |
| 3 | 5/5 | 5/5 | 0/5 | 5/5 | 5/5 | 0/5 | 0/5 | |
| 4 | 5/5 | 5/5 | 0/5 | 5/5 | 5/5 | 0/5 | 0/5 | |
| 5 | 5/5 | 5/5 | 0/5 | 5/5 | 5/5 | 0/5 | 0/5 | |
| Total | 75/75 | 75/75 | 0/75 | 75/75 | 75/75 | 0/75 | 0/75 | |
| Pass(P)/Fail(F) | P | P | P | P | P | P | P |
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4.2 Test Mode Equivalency
The purpose of this study was to qualify the two available test modes of the Acucy 2 System (READ NOW and WALK AWAY) and confirm that they function equivalently. The study was performed by testing twenty (20) replicates each of contrived positive Flu A and Flu B at a concentration of 2x LoD and twenty (20) Flu A and Flu B negative samples (matrix alone) using two (2) Acucy 2 Readers at the same time. One reader was in WALK AWAY mode, and the other in READ NOW mode. One (1) lot of Acucy Influenza A&B kits were used for testing. All testing was done with Influenza A/Michigan and Influenza B/Colorado. On each day of testing, contrived positive samples at 2x LoD (Moderate positive), were prepared by dilution in clinical matrix.
Contrived swabs were prepared by adding 50µL of sample (either contrived positive or negative) to the head of swab. Swabs were dried for 1 minute. All further testing was performed as per Acucy Influenza A&B Instructions for Use (IFU, PN 3248). All tests showed the expected results, positives read as positives in both modes and negatives read as negatives whether in the READ NOW or WALK AWAY mode. The two available test modes function equivalently. The results of the testing are shown in Table 4.
Table 4: Test mode Equivalency Study Results
| Mode → | READ NOW | WALK AWAY | ||
|---|---|---|---|---|
| Sample | Flu A Result | Flu B Result | Flu A Result | Flu B Result |
| Flu A+/B- | 20/20 POS | 20/20 NEG | 20/20 POS | 20/20 NEG |
| Flu A-/B+ | 20/20 NEG | 20/20 POS | 20/20 NEG | 20/20 POS |
| Flu A-/B- Negative | 20/20 NEG | 20/20 NEG | 20/20 NEG | 20/20 NEG |
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4.3 Limit of Detection (LoD)
A comparison of the analytical sensitivity of the Acucy and Acucy 2 readers side by side was performed in a limit of detection (LoD) experiment. For comparing the LoD, two (2) lots of Acucy Influenza A&B assay devices were tested with two (2) strains each of Influenza A (Michigan and Singapore) and two (2) strains each of Influenza B (Phuket and Colorado). A range finding experiment using 5 replicates and 10-fold dilutions of the stock was undertaken on day one (1). After determining the target dilution, for each strain serial two (2) fold dilutions were made corresponding to five low level samples around the expected LoD. These concentrations were tested over three days for a total of 20 replicates per concentration and the lowest concentration at with ≥ 95% of samples were positive was designated the LoD for that lot for the strain tested. Following completion of testing of all strains and both lots the lowest concentration that agrees across both lots was selected as the LoD for that strain.
Confirmation testing was done with 20 replicates once the expected LoD was established. Pooled negative clinical matrix samples were used for preparing dilutions. To create the negative clinical matrix, nasal swab samples were collected from healthy donors and confirmed Flu negative by PCR. Each Flu negative-confirmed nasal swab sample was extracted in 3.0 mL of NCM as per the testing that was done for AcucyTM Influenza A&B Test with the AcucyTM System (K182001). Swab extracts are combined and mixed thoroughly to create a pool of negative clinical matrix to be used as diluent. Contrived swabs in all cases were prepared by adding 50µL of sample to head of swab and dried for one (1) minute. All further testing was performed as per Acucy Influenza A&B Instructions for Use. The results of the LoD testing are shown in Tables 5-7. The results are displayed as Positive detection rate (Number of positives/ Total tested). The LoD for all strains tested on both lots of devices were identical whether tested using Acucy or Acucy 2, confirming that the performance of the Acucy 2 is equivalent to the Acucy.
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Table 5: Range finding experiment to determine the target concentration
| Strain | Concentration (TCID50/mL) | Device A | Device B | ||
|---|---|---|---|---|---|
| Acucy | Acucy 2 | Acucy | Acucy 2 | ||
| Influenza A/Michigan Strain (Stock Conc = 1.41E+05) | 1.41E+04 | 5/5 | 5/5 | 5/5 | 5/5 |
| 1.41E+03 | 5/5 | 5/5 | 5/5 | 5/5 | |
| 1.41E+02 | 5/5 | 5/5 | 5/5 | 5/5 | |
| 1.41E+01 | 0/5 | 0/5 | 0/5 | 0/5 | |
| 1.41E+00 | 0/5 | 0/5 | 0/5 | 0/5 | |
| 1.41E-01 | 0/5 | 0/5 | 0/5 | 0/5 | |
| Influenza A/Singapore Strain (Stock Conc = 3.16E+06) | 3.16E+05 | 5/5 | 5/5 | 5/5 | 5/5 |
| 3.16E+04 | 5/5 | 5/5 | 5/5 | 5/5 | |
| 3.16E+03 | 5/5 | 5/5 | 5/5 | 5/5 | |
| 3.16E+02 | 0/5 | 0/5 | 0/5 | 0/5 | |
| 3.16E+01 | 0/5 | 0/5 | 0/5 | 0/5 | |
| 3.16E+00 | 0/5 | 0/5 | 0/5 | 0/5 | |
| Influenza B/Phuket Strain (Stock Conc = 4.17E+05) | 4.17E+04 | 5/5 | 5/5 | 5/5 | 5/5 |
| 4.17E+03 | 5/5 | 5/5 | 5/5 | 5/5 | |
| 4.17E+02 | 5/5 | 5/5 | 5/5 | 5/5 | |
| 4.17E+01 | 0/5 | 0/5 | 0/5 | 0/5 | |
| 4.17E+00 | 0/5 | 0/5 | 0/5 | 0/5 | |
| 4.17E-01 | 0/5 | 0/5 | 0/5 | 0/5 | |
| Influenza B/Colorado Strain (Stock Conc = 1.41E+05) | 1.41E+04 | 5/5 | 5/5 | 5/5 | 5/5 |
| 1.41E+03 | 5/5 | 5/5 | 5/5 | 5/5 | |
| 1.41E+02 | 4/5 | 4/5 | 0/5 | 1/5 | |
| 1.41E+01 | 0/5 | 0/5 | 0/5 | 0/5 | |
| 1.41E+00 | 0/5 | 0/5 | 0/5 | 0/5 | |
| 1.41E-01 | 0/5 | 0/5 | 0/5 | 0/5 |
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Table 6: Acucy 2 Influenza A&B Test Limit of Detection (LoD) Confirmation Results
| Strain | Concentration (TCID50/mL) | Device A | Device B | ||
|---|---|---|---|---|---|
| Acucy | Acucy 2 | Acucy | Acucy 2 | ||
| Influenza A/Michigan Strain (Stock Conc = 1.41E+05) | 2.82E+02 | 20/20 | 20/20 | 20/20 | 20/20 |
| 1.41E+02 | 17/20 | 17/20 | 18/20 | 18/20 | |
| 7.05E+01 | 5/20 | 4/20 | 2/20 | 4/20 | |
| 3.53E+01 | 2/20 | 0/20 | 0/20 | 0/20 | |
| 1.76E+01 | 0/20 | 0/20 | 0/20 | 0/20 | |
| Influenza A/Singapore Strain (Stock Conc = 3.16E+06) | 6.32E+03 | 20/20 | 20/20 | 20/20 | 20/20 |
| 3.16E+03 | 20/20 | 20/20 | 20/20 | 20/20 | |
| 1.58E+03 | 14/20 | 15/20 | 9/20 | 10/20 | |
| 7.90E+02 | 0/20 | 0/20 | 0/20 | 0/20 | |
| 3.95E+02 | 0/20 | 0/20 | 0/20 | 0/20 | |
| Influenza B/Phuket Strain (Stock Conc = 4.17E+05) | 8.34E+02 | 20/20 | 20/20 | 20/20 | 20/20 |
| 4.17E+02 | 20/20 | 20/20 | 20/20 | 20/20 | |
| 2.09E+02 | 19/20 | 20/20 | 13/20 | 17/20 | |
| 1.04E+02 | 14/20 | 18/20 | 0/20 | 5/20 | |
| 5.20E+01 | 0/20 | 0/20 | 0/20 | 0/20 | |
| Influenza B/Colorado Strain (Stock Conc = 1.41E+05) | 2.82E+02 | 19/20 | 20/20 | NA | NA |
| 1.41E+02 | 9/20 | 17/20 | NA | NA | |
| 7.05E+01 | 1/20 | 3/20 | NA | NA | |
| 3.53E+01 | 0/20 | 0/20 | NA | NA | |
| 1.76E+01 | 0/20 | 0/20 | NA | NA | |
| 2.82E+03 | NA | NA | 20/20 | 20/20 | |
| 1.41E+03 | NA | NA | 20/20 | 20/20 | |
| 7.05E+02 | NA | NA | 20/20 | 20/20 | |
| 3.53E+02 | NA | NA | 17/20 | 17/20 | |
| 1.76E+02 | NA | NA | 3/20 | 5/20 |
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Table 7: Confirmation testing for LoD
| Influenza Strain used | Test Device | LoD Concentration (TCID50/mL) | Acucy | Acucy 2 |
|---|---|---|---|---|
| Influenza A/Michigan Strain | Device A | 2.82E+02 | 20/20 | 20/20 |
| Device B | 2.82E+02 | 20/20 | 20/20 | |
| Influenza A/Singapore Strain | Device A | 3.16E+03 | 20/20 | 20/20 |
| Device B | 3.16E+03 | 20/20 | 20/20 | |
| Influenza B/Phuket Strain | Device A | 2.09E+02 | 20/20 | 20/20 |
| Device B | 4.17E+02 | 20/20 | 20/20 | |
| Influenza B/Colorado Strain | Device A | 2.82E+02 | 20/20 | 20/20 |
| Device B | 7.05E+02 | 20/20 | 20/20 |
4.4 Analytical Cutoff Study
The purpose of this study was to establish the Limit of Blank (LoB) of the Acucy Influenza A&B Assay on the Acucy 2 System by testing sixty (60) replicates of a blank sample per lot to determine the LoB of each lot. Two different device lots were used in testing. Pooled negative clinical matrix samples were used for preparing these samples. 50 µL of contrived specimen was pipetted onto the head of a new nasal swab and dried for one (1) minute. All testing was done per the IFU.
All blank samples showed 0 mABS. In the original study on the Acucy system, the analytical cut-off values were determined to be 6.4 and 5.4 mABS for the Flu A Line and Flu B Line respectively obtained by comparing the assay thresholds of two (2) lots of Acucy Influenza A&B Assay. Acucy 2 was designed to replace Acucy and is expected to be similar to the latter. Under these circumstances the analytical cut-off for Acucy 2 has been set to match the previously established cut-off of 6.4 and 5.4 mABS for Flu A Line and Flu B Line respectively.
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4.5 Cross Contamination Study
The purpose of this study was to evaluate if there is any target carryover between test cassettes leading to cross-contamination between samples when testing the Acucy Influenza A&B test on the Acucy 2 system. The cross-contamination study was evaluated by alternately testing samples at a high titer (1.0 x105 TCID50/ml) and negative samples. This study used one (1) strain of Influenza A and one (1) strain of Influenza B for high titer positive samples and tested on one (1) lot of the Acucy Influenza A&B Test with Acucy 2 System. 120 samples were tested in all, 60 negatives and 30 each of Flu A and Flu B samples. Sample dilutions were prepared. Contrived swabs were prepared by adding 50µL of sample to head of swab. Negative samples were prepared by adding 50µL of negative clinical matrix to the head of a swab. Swabs were dried for 1 minute. All further testing is performed as per Acucy Influenza A&B Instructions for Use (IFU, PN 3248). All testing was done with Influenza A Michigan and Influenza B Colorado. All tests showed expected results as shown in Table 8, positives read as positives and negatives read as negatives.
Table 8: Results of cross contamination study
| Strain | Test ID | Result | Pass/Fail |
|---|---|---|---|
| Flu A | Flu A High Positive (1 - 30) | 30/30 | Pass |
| Flu B | Flu B High Positive (1 - 30) | 30/30 | Pass |
| Negative | No Flu A/B, matrix | 60/60 | Pass |
4.6 Method Comparison - Acucy Reader vs. Acucy 2 Reader
A comparison study was conducted to establish performance equivalence between the Acucy and Acucy 2 Readers. Thirty (30) samples each of PCR confirmed Flu A positive and Flu B positive clinical samples and thirty (30) Flu A and Flu B negative clinical samples were tested using one (1) Acucy Reader and one (1) Acucy 2 Reader with one (1) lot of Acucy Influenza A&B test kits. The Flu A positive samples were considered negatives for Flu B, and those positive for Flu B were considered negative for Flu A. Together, including double negative samples, there were a total of 60 negatives for each group. These samples were representative of a range of virus levels with RT-PCR values ranging from Ct 11.5 - 32.4.
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Table 9: Influenza A, Method Comparison Study Results
Test: Acucy Influenza A&B Test with Acucy System
| Comparative: Acucy Influenza A&B Test with Acucy 2 System | Flu A Positive | Flu A Negative | Total |
|---|---|---|---|
| Flu A Positive | 30 | 1* | 31 |
| Flu A Negative | 0 | 59 | 59 |
| Total | 30 | 60 | 90 |
| Performance | PPA: 100% | NPA: 98.3% |
*Confirmed Flu B positive sample generated a double positive result.
Table 10: Influenza B, Method Comparison Study Results
Test: Acucy Influenza A&B Test with Acucy System
| Comparative: Acucy Influenza A&B Test with Acucy 2 System | Flu B Positive | Flu B Negative | Total |
|---|---|---|---|
| Flu B Positive | 30 | 0 | 30 |
| Flu B Negative | 0 | 60 | 60 |
| Total | 30 | 60 | 90 |
| Performance | PPA: 100% | NPA: 100% |
5. CLIA Waiver Studies
5.1 Flex Studies
These studies were carried out to characterize operator workflow and usability risks identified with use of the Acucy Influenza A&B test on the Acucy 2 System by simulating conditions where the test was performed outside the intended use instructions and environment and the Acucy 2 Reader differed from the Acucy Reader. Each flex study was conducted using sample panel (Negative, Low Positive (2x LoD) Flu A, and Low Positive (2x LoD) Flu B) tested in five (5) replicates for every flex condition using one (1) lot of Acucy Influenza A&B kit.
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The following flex studies were performed:
- Temperature and Humidity
- Vibrations from surrounding instruments
- Environmental lighting
- Air Draft conditions
- Operational altitude/barometric pressure
- Non-level reader position
- Contamination of Cassette Read Window
- Movement of Acucy 2 Reader in WALK AWAY mode
- Movement of test cassette and vertical incubation
- Positioning of Acucy test in reader drawer
Based on the results of the flex testing, all the hazards and sources of potential error have been controlled to reasonably acceptable levels through design features and appropriate labelling mitigations.
5.2 Reproducibility
The reproducibility of the Acucy Influenza A&B Test was evaluated on the Acucy Reader in testing performed at three point-of-care (POC) sites. A panel of swabs including negative (no virus), high negative (below the limit of detection), low positive (at or near the limit of detection) and moderate positive (at or near 2x the limit of detection) for influenza A and B were coded, randomized, and masked to the operators. The study was conducted with two operators per site over five non-consecutive days. As seen in the table below, the Acucy Influenza A&B Test produces reproducible results when tested by multiple intended users, at multiple sites, over multiple days.
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Table 11: Acucy Influenza A, External Multi-Site Reproducibility Study Results
| Sample | Site 1 | Site 2 | Site 3 | Total |
|---|---|---|---|---|
| Influenza A (H3N2) High Negative | 100% (30/30) | 100% (30/30) | 96.7% (29/30) | 98.9% (89/90) |
| Influenza A (H3N2) Low Positive | 100% (30/30) | 100% (30/30) | 100% (30/30) | 100% (90/90) |
| Influenza A (H3N2) Moderate Positive | 100% (30/30) | 100% (30/30) | 100% (30/30) | 100% (90/90) |
| Negative | 100% (30/30) | 100% (30/30) | 100% (30/30) | 100% (90/90) |
Table 12: Acucy Influenza B, External Multi-Site Reproducibility Study Results
| Sample | Site 1 | Site 2 | Site 3 | Total |
|---|---|---|---|---|
| Influenza B High Negative | 100% (30/30) | 100% (30/30) | 100% (30/30) | 100% (90/90) |
| Influenza B Low Positive | 100% (30/30) | 100% (30/30) | 100% (30/30) | 100% (90/90) |
| Influenza B Moderate Positive | 100% (30/30) | 100% (30/30) | 96.7% (29/30) | 98.9% (89/90) |
| Negative | 100% (30/30) | 100% (30/30) | 100% (30/30) | 100% (90/90) |
Supplementary Reproducibility Study
The reproducibility of the Acucy Influenza A&B Test was evaluated on the Acucy 2 Reader in testing performed at three laboratory sites. A panel of swabs including negative (no virus), high negative (below the limit of detection), low positive (at or near the limit of detection) and moderate positive (at or near 2x the limit of detection) for influenza A and B were coded, randomized, and masked to the operators. The study was conducted with two operators per site over five non-consecutive days. As seen in the tables below, the Acucy Influenza A&B Test produces reproducible results when tested by multiple intended users, at multiple sites, over multiple days.
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510(k) Summary (K231187)
Acucy Influenza A&B Test with the Acucy 2 System
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Table 13: Acucy 2 Influenza A, External Multi-Site Reproducibility Study Results
| Sample | Site 1 | Site 2 | Site 3 | Total |
|---|---|---|---|---|
| Influenza A High Negative | 100% (30/30) | 100% (30/30) | 100% (30/30) | 100% (90/90) |
| Influenza A Low Positive | 100% (30/30) | 100% (30/30) | 100% (30/30) | 100% (90/90) |
| Influenza A Moderate Positive | 100% (30/30) | 100% (30/30) | 100% (30/30) | 100% (90/90) |
Table 14: Acucy 2 Influenza B, External Multi-Site Reproducibility Study Results
| Sample | Site 1 | Site 2 | Site 3 | Total |
|---|---|---|---|---|
| Influenza B High Negative | 100% (30/30) | 100% (30/30) | 100% (30/30) | 100% (90/90) |
| Influenza B Low Positive | 100% (30/30) | 100% (30/30) | 100% (30/30) | 100% (90/90) |
| Influenza B Moderate Positive | 100% (30/30) | 100% (30/30) | 100% (30/30) | 100% (90/90) |
Table 15: Acucy 2 Negative, External Multi-Site Reproducibility Study Results
| Sample | Site 1 | Site 2 | Site 3 | Total |
|---|---|---|---|---|
| Influenza A & B Negative | 100% (30/30) | 100% (30/30) | 100% (30/30) | 100% (90/90) |
Conclusion
The results of the studies summarized above demonstrate that the Acucy 2 Instrument with Influenza A/B is substantially equivalent to the stated predicate device.