Focus Technologies' HerpeSelect® 1 ELISA IgG test is intended for qualitatively detecting the presence or absence of human IgG class antibodies to HSV-1 in human sera. In conjunction with the Focus HerpeSelect® 2 ELISA IgG, the test is indicated for testing sexually active adults or expectant mothers for aiding in the presumptive diagnosis of HSV infection. The assay can be used manually or in conjunction with an automated system as outlined in the package insert. The user is responsible for assay performance characteristics when an automated system is used. The performance of this assay has not been established for use in a pediatric population, for neonatal screening, or for testing of immunocompromised patients.
Device Story
The HerpeSelect® 1 ELISA IgG is an in vitro diagnostic assay using polystyrene microwells coated with recombinant gG-1 antigen. Diluted serum samples and controls are incubated in wells; specific antibodies bind to the antigen. After washing, peroxidase-conjugated anti-human IgG is added, followed by enzyme substrate and chromogen to produce a color change. The reaction is stopped, and optical density (OD) is measured via spectrophotometry. Results are determined by comparing sample OD to reference cut-off OD values. The device is used in clinical laboratories, either manually or with an automated system. Healthcare providers use the qualitative results to aid in the presumptive diagnosis of HSV-1 infection in conjunction with HerpeSelect® 2 ELISA IgG. The assay provides clinicians with serological information to support patient management decisions.
Clinical Evidence
Clinical performance evaluated using archived, masked sera from sexually active adults (n=246) and expectant mothers (n=241) compared to Western blot reference. In expectant mothers, sensitivity was 96.0% (95% CI: 92.0-98.4%) and specificity was 95.2% (95% CI: 86.5-99.0%). In sexually active adults, sensitivity was 91.2% (95% CI: 85.2-95.4%) and specificity was 92.3% (95% CI: 85.4-96.6%). Additional testing included culture-positive patients, CDC panels, and cross-reactivity studies with related viruses (CMV, EBV, HHV6, VZV). Reproducibility studies (intra-assay, inter-assay, inter-lot, inter-laboratory) were performed.
Technological Characteristics
Polystyrene microwells coated with recombinant gG-1 antigen; enzyme-linked immunosorbent assay (ELISA) principle; spectrophotometric detection of optical density; manual or automated platform compatibility; requires peroxidase-conjugated anti-human IgG and enzyme substrate/chromogen.
Indications for Use
Indicated for sexually active adults and expectant mothers to aid in the presumptive diagnosis of HSV-1 infection via qualitative detection of human IgG class antibodies in serum. Not established for pediatric populations, neonatal screening, or immunocompromised patients.
Regulatory Classification
Identification
Herpes simplex virus serological assays are devices that consist of antigens and antisera used in various serological tests to identify antibodies to herpes simplex virus in serum. Additionally, some of the assays consist of herpes simplex virus antisera conjugated with a fluorescent dye (immunofluorescent assays) used to identify herpes simplex virus directly from clinical specimens or tissue culture isolates derived from clinical specimens. The identification aids in the diagnosis of diseases caused by herpes simplex viruses and provides epidemiological information on these diseases. Herpes simplex viral infections range from common and mild lesions of the skin and mucous membranes to a severe form of encephalitis (inflammation of the brain). Neonatal herpes virus infections range from a mild infection to a severe generalized disease with a fatal outcome.
Special Controls
*Classification.* Class II (special controls). The device is classified as class II (special controls). The special control for the device is FDA's revised guidance document entitled “Class II Special Controls Guidance Document: Herpes Simplex Virus Types 1 and 2 Serological Assays.” For availability of the guidance revised document, see § 866.1(e).
Predicate Devices
HerpeSelect® 1 ELISA IgG (manual option)
Submission Summary (Full Text)
{0}------------------------------------------------
JUL 2 9 2002
Image /page/0/Picture/1 description: The image shows the logo for Focus Technologies. The logo is black and white and features the word "FOCUS" in large, bold letters. Below the word "FOCUS" is the word "technologies" in smaller letters. The two crescent moon shapes are used in place of the letter "O" in the word "FOCUS".
510(k) Summarv of Safety and Effectiveness HerpeSelect® 1 ELISA IgG Catalog No. EL0910G Prepared July 23, 2002 Page 1 of 9
K021429
| Applicant | Focus Technologies, Inc.<br>10703 Progress Way<br>Cypress, California 90630<br>USA |
|-----------------------------------|-------------------------------------------------------------------------------------------------|
| Establishment<br>Registration No. | 2023365 |
| Contact Person | Michael J. Wagner, Esq.<br>tel (714) 220-1900<br>fax (714) 995-6921<br>mwagner@focusanswers.com |
| Summary Date | July 23, 2002 |
| Proprietary Name | HerpeSelect®1 ELISA IgG (automated option) |
| Generic Name | HSV-1 ELISA IgG |
| Classification | Herpes Simplex Virus Serological Reagents<br>21 CFR §866.3305<br>Class III |
| Predicate Device | HerpeSelect®1 ELISA IgG (manual option) |
### Device Description
In the HerpeSelect® I ELISA IgG IgG assay, the polystyrene microwells are coated with recombinant gG-1 antigen. Diluted serum samples and controls are incubated in the wells to allow specific antibody present in the samples to react with the antigen. Nonspecific reactants are removed by washing, and peroxidase-conjugated anti-human IgG is added and reacts with specific IgG. Excess conjugate is removed by washing. Enzyme substrate and chromogen are added, and the color is allowed to develop. After adding the Stop Reagent, the resultant color change is quantified by a spectrophotometric reading of optical density (OD). Sample optical density readings are compared with reference cut-off OD readings to determine results.
### Intended Use
Focus Technologies' HerpeSelect® 1 ELISA IgG test is intended for qualitatively detecting the presence or absence of human IgG class antibodies to HSV-1 in human sera. In conjunction with the Focus HerpeSelect® 2 ELISA IgG, the test is indicated for testing sexually active adults or expectant mothers for aiding in the presumptive diagnosis of HSV infection. The assay can be used manually or in conjunction with an automated system as outlined in the package insert. The user is responsible for assay performance characteristics when an automated system is used. The performance of this assay has not been established for use in a pediatric population, for neonatal screening, or for testing of immunocompromised patients.
{1}------------------------------------------------
# 510(k) Summary of Safety and Effectiveness HerpeSelect® 1 ELISA IgG Catalog No. EL0910G Prepared July 23, 2002 Page 2 of 9
# EXPECTED VALUES
An outside investigator assessed the device with masked, archived and unselected sera from 1) sexually active adults over the age of 14 (n = 246), and 2) from expectant mothers (n = 241). The reference method was a HSV-1 Western blot from a Pacific Northwest university. The observed prevalences and the hypothetical predictive values for the two populations are shown in the tables below. The positive value will decrease proportionally to the prevalence of HSV infection as reflected in the table below. The calculations are based on HerpeSelect® 1 ELISA IgG having
1) a hypothetical sensitivity of 91.2% & a hypothetical specificity of 92.3% (sexually active adults), and
2) a hypothetical sensitivity of 96.0% and a hypothetical specificity of 95.2% (expectant mothers).
| Population | HSV-1<br>Serostatus | Observed Prevalence | |
|--------------------------|---------------------|---------------------|-------------|
| | | WB | Focus ELISA |
| Sexually Active Adults * | neg | 42.9% | 41.2% |
| | + | 55.9% | 56.7% |
| Expectant Mothers † | neg | 25.7% | 22.4% |
| | + | 73.9% | 75.5% |
# Observed Prevalence with Sexually Active Adults & Expectant Mothers
* Excludes 3 atvpical Western blots and 2 ELISA equivocals.
+ Excludes 1 atypical Western blot and 1 ELISA equivocal.
| Prevalence | Sexually Active Adults | | Expectant Mothers | |
|------------|------------------------|-------|-------------------|-------|
| | PPV | NPV | PPV | NPV |
| 50% | 92.2% | 92.3% | 95.2% | 95.2% |
| 40% | 88.8% | 94.7% | 93.0% | 96.7% |
| 30% | 83.5% | 96.5% | 89.6% | 97.9% |
| 25% | 79.8% | 97.3% | 87.0% | 98.3% |
| 20% | 74.8% | 98.0% | 83.3% | 98.8% |
| 15% | 67.6% | 98.5% | 77.9% | 99.1% |
| 10% | 56.8% | 99.1% | 69.0% | 99.4% |
| 5% | 38.4% | 99.6% | 51.3% | 99.7% |
### Prevalence vs. Hypothetical Predictive Values
Note: Sexually active adult and expectant mother populations in different geographic areas may produce different frequency distributions from the table above. Each laboratory should establish frequency distributions for their specific patient populations.
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Image /page/2/Picture/1 description: The image shows the logo for Focus Technologies. The word "FOCUS" is written in large, bold, sans-serif font, with two crescent moon shapes forming the letter "O". Below the word "FOCUS", the word "technologies" is written in a smaller, sans-serif font, with each letter spaced out.
510(k) Summary of Safety and Effectiveness HerpeSelect® 1 ELISA IgG Catalog No. EL0910G Prepared July 23, 2002 Page 3 of 9
# PERFORMANCE CHARACTERISTICS
### Relative Sensitivity and Relative Specificity with Expectant Mothers +
An outside investigator assessed the device's relative specificity with sera from expectant mothers (n = 241). The sera were sequentially submitted to the laboratory, archived, and masked. The reference method was a HSV-1 Western blot (WB) from a Pacific Northwest university. Of 178 WB positives, HerpeSelect® 1 ELISA IgG (EL) was 170 positive, 7 negative and one equivocal. Of 62 Western blot negatives, HerpeSelect® 1 ELISA IgG was 59 negatives, and 3 positives. The one atypical Western blot was HerpeSelect® 1 ELISA IgG negative.
| Relative Sensitivity and Relative Specificity with Expectant Mothers (n=241) 1 |
|--------------------------------------------------------------------------------|
|--------------------------------------------------------------------------------|
| Characteristic | % (EL/WB)* | 95% CI |
|--------------------------------------|-----------------|------------|
| Sensitivity relative to Western blot | 96.0% (170/177) | 92.0-98.4% |
| Specificity relative to Western blot | 95.2% (59/62) | 86.5-99.0% |
* Excludes one atypical Western blot and one ELISA equivocal.
+ The word "relative" refers to comparing this assay's results with those of a similar assay. No attempt was made to correlate the assay results to disease presence or absence. No judgment can be made on the similar assay's accuracy in predicting disease. Assay performed by the manual method.
### Relative Sensitivity and Relative Specificity with Sexually Active Adults +
An outside investigator assessed the device's relative sensitivity and relative specificity with sera from sexually active adults over the age of 14 (n = 246). The sera were sequentially submitted to the laboratory, archived, and masked. The reference method was a HSV-1 Western blot from a Pacific Northwest university. Of 138 Western blot positives, HerpeSelect® 1 ELISA IgG was 125 positive, 12 negatives, and one equivocal. Of 105 Western blot Western blots, HerpeSelect® 1 ELISA IgG was one negative and two positives.
Relative Sensitivity and Relative Specificity with Sexually Active Adults (n = 246) +
| Characteristic | % (EL/WB)* | 95% CI |
|--------------------------------------|-----------------|------------|
| Sensitivity relative to Western blot | 91.2% (125/137) | 85.2-95.4% |
| Specificity relative to Western blot | 92.3% (96/104) | 85.4-96.6% |
* Excludes three atypical Western blots and two ELISA equivocals.
The word "relative" refers to comparing this assay's results with those of a similar assay. No attempt was made to correlate the assay results to disease presence or absence. No judgment can be made on the similar assay's accuracy in predicting disease. Assay performed by the manual method.
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Image /page/3/Picture/1 description: The image shows the logo for Focus Technologies. The logo consists of the word "FOCUS" in a bold, sans-serif font, with a crescent moon shape incorporated into the letter "O". Below the word "FOCUS" is the word "technologies" in a smaller, sans-serif font. The logo is black and white.
### Relative Sensitivity with Culture Positives †
An outside investigator assessed the device's relative sensitivity using sera from culture positive patients (n = 38). Reference methods included culture (infection) and a HSV-1 Western blot (antibody) from a Pacific Northwest university. Of 38 culture positives: 1) Western blot was 37 positive and one negative; and 2) HerpeSelece 1 ELISA IgG was 30 positive and eight negative. Of the 37 Western blot positives, HerpeSelect® 1 ELISA IgG was 30 positive and seven negatives.
| Characteristic | % (EL/WB or<br>Culture) | 95% CI |
|--------------------------------------|-------------------------|------------|
| Sensitivity relative to culture | 78.9% (30/38) | 62.7-90.4% |
| Sensitivity relative to Western Blot | 81.1% (30/37) | 64.8-92.0% |
### Relative Sensitivity with Culture Positives (n = 38) +
+ The word "relative" refers to comparing this assay's results with those of a similar assay. No attempt was made to correlate the assay results to disease presence or absence. No judgment can be made on the similar assay's accuracy in predicting disease. Assay performed by the manual method.
# Agreement with CDC Panel +
The following information is from a serum panel obtained from the CDC and tested by Focus Technologies. The results are presented as a means to convey further information on the performance of this assay with a masked. characterized serum panel. This does not imply an endorsement of the assay by the CDC. The panel consists of 59% positive and 41% negative samples. The Focus Technologies HerpeSelect® 1 ELISA IgG demonstrated 96.0% total agreement with the CDC results. Of the results obtained by Focus Technologies, there was 93.1% agreement with the positive specimens and 100% agreement with the negative specimens.
* Assay performed by the manual method.
### Relative Specificity with a Low Prevalence Population *
An outside investigator assessed the device's relative specificity using sera from a population of college students claiming to lack sexual experience (n = 81), and having a published HSV-1 antibody prevalence of 26.9% (50/186).13 The laboratory reference method was a HSV-1 Western blot from a Pacific Northwest university. Of 57 Western blot negatives, HerpeSelect® 1 ELISA IgG was 55 negatives, 1 positive and 1 equivocal. Of 24 Western blot positives, HerpeSelect® 1 ELISA IgG was 18 positive and 6 negatives.
| Characteristic | % (EL/WB)* | 95% CI |
|--------------------------------------|---------------|------------|
| Specificity relative to Western blot | 98.2% (55/56) | 90.5-100% |
| Sensitivity relative to Western blot | 75.0% (18/24) | 53.3-90.2% |
Relative Specificity with a Low Prevalence Population (n = 81) *
* Excludes one ELISA equivocal.
* The word "relative" refers to comparing this assay's results with those of a similar assay. No attempt was made to correlate the assay results to disease presence or absence. No judgment can be made on the similar assay's accuracy in predicting disease. Assay performed by the manual method.
{4}------------------------------------------------
Image /page/4/Picture/1 description: The image shows the logo for Focus Technologies. The logo is black and white and features the word "FOCUS" in large, bold letters. Below the word "FOCUS" is the word "technologies" in smaller letters. The letter "O" in the word "FOCUS" is replaced with a crescent moon shape.
# 510(k) Summary of Safety and Effectiveness HerpeSelect® 1 ELISA IgG Catalog No. EL0910G Prepared July 23, 2002 Page 5 of 9
Type Specificity with HSV-2 Western Blot Positives †
An outside investigator assessed the device's type specificity using HSV-2 Western blot positive and HSV-1 Western Blot negative sera from the above described populations (n = 90): expectant mothers, sexually active adults, low prevalence persons, and HSV-2 culture positives. Of 90 HSV-2 Western blot positive and HSV-1 Western blot negative samples, HerpeSelect® 1 ELISA IgG was 82 negatives, and eight positives.
| Characteristic | % (EL/WB) | 95% CI |
|--------------------------------------|---------------|------------|
| Type-specificity relative to WB | 91.1% (82/90) | 83.2-96.1% |
| Type cross-reactivity relative to WB | 8.9% (8/90) | 3.9-16.8% |
### Type Specificity with HSV-2 Western Blot Positives (n = 90)
+ The word "relative" refers to comparing this assay's results with those of a similar assay. No attempt was made to correlate the assay results to disease presence or absence. No judgment can be made on the similar assay's accuracy in predicting disease. Assay performed by the manual method.
# Cross-reactivity with Taxonomically Related Viruses †
Focus assessed the device's cross-reactivity using sera (n = 26) that were 1) HSV sero-negative by another manufacturer's FDA cleared HSV ELISAs, and 2) IFA IgG positive for taxonomically similar viruses including CMV, EBV VCA, HHV6 and VZV. Discrepants between the FDA cleared HSV ELISAs and the HerpeSelect® 1 ELISA IgG were analyzed using a type specific Western blot from a major university located in the Northwestern United States. Excluding one HerpeSelect® 1 ELISA IgG equivocal that was not analyzed with the Western blot because of insufficient volume.
| IFA IgG Pos | % Focus EL Neg | 95% CI |
|-------------|----------------|-----------|
| CMV | 100% (12/12) | 73.5-100% |
| EBV VCA | 100% (24/24) | 85.5-100% |
| HHV6 | 100% (24/24) | 85.5-100% |
| VZV | 100% (23/23) | 85.2-100% |
| Total | 100% (83/83) | 95.7-100% |
| | Cross-reactivity with Taxonomically Related Viruses | |
|--|-----------------------------------------------------|--|
|--|-----------------------------------------------------|--|
* Assay performed by the manual method.
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Image /page/5/Picture/0 description: The image shows the alphanumeric string "K021429" in a bold, sans-serif font. The characters are large and clearly legible against a white background. The string appears to be a code or identifier, possibly a serial number or product code.
Image /page/5/Picture/1 description: The image shows the logo for Focus Technologies. The logo consists of the word "FOCUS" in large, bold letters, with two crescent moon shapes forming the letter "O". Below the word "FOCUS" is the word "technologies" in smaller letters. The logo is simple and modern, and the use of the crescent moon shapes gives it a unique and memorable look.
### Intra-assay and Inter-assay Reproducibility †
An internal investigator assessed the device's intra-assay reproducibility by assaying seven samples in duplicate, twice a day, for twenty days, for a total of forty runs. Two sets of samples were masked duplicates.
# Inter-lot Reproducibility †
An internal investigator assessed the device's inter-lot reproducibility. Seven samples were run on in duplicate and in parallel with three separate lots. Each of the three lots had at least a different lot of Antigen Wells.
# Inter-laboratory Reproducibility †
An internal investigator and two off site laboratories assessed the device's inter-laboratory reproducibility. Each of the three laboratories ran seven samples in triplicate on three different days.
| Sample | Inter- & Intra-assay | | | Inter-lot | | Inter-Laboratory | | |
|--------|----------------------|------------------------|------------------------|---------------|--------------|------------------|------------------------|------------------------|
| | Index<br>Mean | Intra-<br>assay<br>%CV | Inter-<br>assay<br>%CV | Index<br>Mean | Index<br>%CV | Index<br>Mean | Mean of<br>Lab<br>%CVs | %CV of<br>Lab<br>Means |
| 11* | 0.1 | 40.0 | 50.4 | 0.1 | 26.8 | 0.2 | 6.6 | 70.9 |
| 16* | 0.1 | 0.0 | 11.6 | 0.1 | 20.2 | 0.2 | 23.6 | 63.1 |
| 12** | 1.6 | 3.8 | 7.0 | 1.5 | 8.2 | 1.4 | 13.5 | 7.0 |
| 17** | 1.6 | 40.0 | 5.4 | 1.4 | 2.9 | 1.5 | 13.0 | 4.3 |
| 13 | 2.7 | 3.6 | 4.9 | 2.5 | 11.1 | 2.4 | 10.8 | 5.7 |
| 14 | 3.1 | 3.9 | 6.5 | 2.6 | 9.4 | 2.7 | 10.7 | 7.5 |
| 15 | 12.0 | 2.2 | 5.6 | 10.9 | 25.1 | 14.2 | 24.3 | 64.6 |
* #11 & #16 are masked duplicates.
** #12 & #17 are masked duplicates.
† Assay performed by the manual method
{6}------------------------------------------------
Image /page/6/Picture/1 description: The image shows the logo for Focus Technologies. The logo consists of the word "FOCUS" in bold, sans-serif font, with two crescent moon shapes forming the letter "O". Below the word "FOCUS" is the word "technologies" in a smaller, sans-serif font. The logo is black and white.
510(k) Summary of Safety and Effectiveness HerpeSelect® 1 ELISA IgG Catalog No. EL0910G Prepared July 23, 2002 Page 7 of 9
% Agreement between the Manual and Automated Methods
An internal and an external investigator compared % agreement between the HerpeSelect automated method vs. the manual method as part of a CLIA validation for a major clinical laboratory located in Southern California. The external investigator sequentially selected and manually tested 248 sample was from an adult, and was submitted for HSV testing. 246 samples were from the US, and two samples from outside the US. Of the 248 samples, the manual method detected 108 negatives, 3 equivocals, and 137 positives. Of the 108 negatives by the manual method, the automated method agreed with 98.1% (106/108). Of the 3 equivocals by the manual method, the automated method agreed with 66.7% (2/3). Of the 137 positives by the manual method, the automated method agreed with 97.8% (134/137). Overall, the two methods agreed 97.6% (242/248). Of the five discrepants, three resolved in favor of the automated method, and the other two did not resolve.
| Interpretation* | % Agreement | 95% CI |
|-----------------|-----------------|------------|
| Negative | 98.1% (106/108) | 93.5-99.8% |
| Equivocal | 66.7% (2/3) | 9.4-99.2% |
| Positive | 97.8% (134/137) | 93.7-99.5% |
| Overall | 97.6% (242/248) | 94.8-99.1% |
# % Agreement between the Manual and Automated Methods
* Interpretation by manual method.
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Image /page/7/Picture/1 description: The image shows the logo for Focus Technologies. The logo is in black and white. The word "FOCUS" is in large, bold letters, with a crescent moon shape replacing the letter "O". Below the word "FOCUS" is the word "technologies" in smaller letters.
# 510(k) Summary of Safety and Effectiveness HerpeSelect® 1 ELISA IgG Catalog No. EL0910G Prepared July 23, 2002 Page 8 of 9
# Reproducibility Using an Automated Instrument
An internal investigator assessed the device's inter-assay reproducibility with an automated instrument. Ten samples were tested in triplicate on three different days. The manual and automated methods agreed 98.9% (89/90). One point from Sample 3 was an outlier (162 standard deviations from the mean).
| Sample | Mean Index | Intra-assay<br>%CV | Inter-assay<br>%CV |
|--------|------------|--------------------|--------------------|
| 2 | 0.2 | 7.8 | 17.5 |
| 7 | 0.3 | 9.8 | 3.1 |
| 8 | 0.4 | 6.7 | 6.1 |
| 10 | 1.2 | 4.4 | 6.2 |
| 9 | 2.0 | 7.6 | 7.0 |
| 4 | 3.0 | 15.7 | 3.9 |
| 5 | 3.9 | 6.8 | 6.1 |
| 3 | 5.3 | 14.0 | 2.2 |
| 1 | 5.6 | 13.5 | 1.4 |
| 6 | 7.6 | 5.0 | 8.0 |
# Reproducibility Using an Automated Instrument
{8}------------------------------------------------
Image /page/8/Picture/1 description: The image shows the logo for Focus Technologies. The logo is in black and white and features the word "FOCUS" in large, bold letters. Below the word "FOCUS" is the word "technologies" in smaller letters. The two letter O's in the word FOCUS are replaced with a crescent moon shape.
# 510(k) Summary of Safety and Effectiveness HerpeSelect® 1 ELISA IgG Catalog No. EL0910G Prepared July 23, 2002 Page 9 of 9
### Stability after Opening Reagents
An internal investigator assessed stability after the reagents had been opened. The kit was used in the interassay/intra-assay reproducibility study (above), re-closed, stored at 2-8C for at least 30 days, and then used again to re-test the same samples. The index for when the reagents were opened and the two runs after at least 30 days are provided below. There was 96.7% agreement with the index when the reagents were opened.
| Sample | Index when<br>Opened | After at Least<br>30 Days (Run 1) | After at Least<br>30 Days (Run 2) |
|--------|----------------------|-----------------------------------|-----------------------------------|
| 2 | 0.2 | 0.2 | 0.2 |
| 7 | 0.3 | 0.3 | 0.4 |
| 8 | 0.4 | 0.3 | 0.5 |
| 10 | 1.2 | 1.1 | 1.6 |
| 9 | 2.0 | 1.8 | 2.4 |
| 4 | 3.0 | 2.8 | 3.4 |
| 5 | 3.9 | 3.4 | 4.5 |
| 3 | 5.3 | 4.7 | 5.9 |
| 1 | 5.6 | 5.3 | 6.4 |
| 6 | 7.6 | 6.7 | 7.8 |
### Stability after Opening Reagents
{9}------------------------------------------------
DEPARTMENT OF HEALTH & HUMAN SERVICES
Image /page/9/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a circular seal with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES (USA)" arranged around the perimeter. Inside the circle is a stylized symbol that resembles three wavy lines or ribbons, which is the department's official emblem.
Food and Drug Administration 2098 Gaither Road Rockville MD 20850
JUL 2 9 2002
Michael J. Wagner, Esq. Senior Regulatory Affairs Specialist Focus Technologies, Inc. 10703 Progress Way Cypress. CA 90630
K021429 Re:
> Trade/Device Name: HerpeSelect TM 1 ELISA IgG Regulation Number: 21 CFR 866.3305 Regulation Name: Herpes Simplex Virus Serological Reagents Regulatory Class: Class III Exempt Product Code: MXJ Dated: May 2, 2002 Received: May 3, 2002
Dear Mr. Wagner:
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 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.
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); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
{10}------------------------------------------------
Page 2 -
This letter will allow you to begin marketing your device as described in your 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 advice for your device on our labeling regulation (21 CFR Part 801 and 1 additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4588. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR 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/cdrb/dsmaldsmamain.html".
Sincerely yours,
Steven Butman
Steven I. Gutman, M.D., M.B.A. Director Division of Clinical Laboratory-Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
{11}------------------------------------------------
Page 1 of 1
510(k) Number (if known):K021429
Device Name:
HerpeSelect® 1 ELISA IgG
Indications for Use:
Focus Technologies' HerpeSelect® 1 ELISA IgG test is intended for qualitatively detecting the presence or absence of human IgG class antibodies to HSV-1 in human sera. In conjunction with the Focus HerpeSelect® 2 ELISA IgG, the test is indicated for testing sexually active adults or expectant mothers for aiding in the presumptive diagnosis of HSV infection. The assay can be used manually or in conjunction with an automated system as outlined in the package insert. The user is responsible for assay performance characteristics when an automated system is used. The performance of this assay has not been established for use in a pediatric population, for neonatal screening, or for testing of immunocompromised patients.
(PLEASE DO NOT WRITE BELOW THIS LINE CONTINUE ON ANOTHER PAGE IF NEEDED) Concurrence of CDRH, Office of Device Evaluation (ODE)
Woody Dubois
FOR PRESCRIPTION USE _X
(Optional Format 3-10-98)
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1. Search: exact and fuzzy
Type a phrase like "coronary artery calcification" into the search box. You get two kinds of results. Exact results match the literal phrase — prefix searches work ("coronary artery calcificati") but suffix searches do not. Fuzzy results match on the meaning and intent of your phrase rather than the exact words, and are sorted by relevance score. Hover over the Exact or Fuzzy badge on any row to see exactly why it matched.
Use the checkboxes above the results to narrow: SaMD keeps only software-only devices, AI / ML keeps only devices with AI.
Exact vs. fuzzy search: what's the difference?
Exact matches on the literal phrase (prefix search works, suffix does not). Fuzzy matches on the meaning and intent of the phrase rather than the exact words. Hover over the badge on any row to see why it matched.
You search "coronary artery calcification" and want only software devices with AI. What two filters do you apply?
Narrow by SaMD (software-only devices), then narrow by AI/ML (devices with AI).
2. The results table
Scroll right in the results table. The intended use is extracted for you — no need to open the PDF. The device story gives a high-level snapshot of what the device does and how it's used. The AI Performance sub-table shows each output name, acceptance criteria, observed values, and development/test dataset descriptions — the same format Innolitics uses for regulatory strategy outputs, and the fastest high-level fingerprint of an AI device. It is AI-generated but has been very reliable in practice.
Where do you find a device's intended use without opening the PDF?
Scroll right in the search results table. The intended use column is extracted for you; no need to dig into the 510(k) summary PDF.
What does the AI Performance sub-table show, and why is it useful?
Output name, acceptance criteria, observed values, development dataset description, and test dataset description. It's the same format we use for regulatory strategy output and Fast 510(k) input, and the fastest high-level fingerprint of an AI device. AI-generated but reliable in practice.
3. Judging fuzzy relevance
Fuzzy results trail off in relevance as you scroll. Use three signals to decide how far down to go: the fuzzy badge explanations, the intended use column, and whether your target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, you're past the relevant zone. A top hit with a low score (~0.4) and a stretched explanation is a hint the closest predicates are far away — the project may be headed for De Novo. Note the fuzzy search is a pattern match: it doesn't handle negation ("not") well, and hardware devices can appear — filter by SaMD/AI ML to cut them.
How do you judge how far down fuzzy search results to go?
Use the relevancy signals: the fuzzy badge explanations, the intended use column, and whether the target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, results are trailing off in relevancy.
4. Device detail page: chat and citations
Click a device name to open its detail page: device facts on the left, a chat window on the right. Ask something like "Describe the training data". The answer carries little citation bubbles — click one to jump to the highlighted passage in the source PDF, so you can verify every AI answer against the document. There's also a Download PDF button for sharing.
How do you verify an AI chat answer on the device detail page?
Click the citation bubbles to jump to the relevant highlight in the source document.
Reading rule for every project: how many summaries do you read in full?
At least the three most relevant 510(k) or De Novo summaries, in full. After that, use targeted chat questions to confirm your memory quickly. The tool supports this professional habit — it doesn't replace it.
5. Side-by-side comparison
Select multiple rows in the results table (aim for under ~10), then open the PDF Viewer tab. Ask one question — it goes to all selected devices in parallel, each with citations. This is the fastest way to compare and contrast devices: training data, PCCP scope, how they handled adding new scanners, and so on.
What does the side-by-side PDF viewer mode do?
Select multiple devices, open the PDF viewer tab, and ask one question (e.g., "Describe the training data"). It queries all selected devices simultaneously with citations, so you can compare and contrast quickly.
6. Collections
With rows selected, go to the Collections tab and create a labeled collection (e.g., "Cobb Angle Project"). Reload that selection any time — before a client call, pull up the collection and ask questions across all of its devices at once.
How do you save a set of selected devices for later use?
Select the rows, go to the Collections tab, and create a labeled collection (e.g., "Cobb Angle Project"). You can reload the selection anytime and carry it into the PDF viewer and other tabs that support selections.
7. Product codes and the regulations tree
Click a product code in the results to jump to it in the regulations tree — identification text, sibling product codes, and devices you can open in a PDF viewer on the right. Click a regulation number to see its identification, special controls, and related product codes. You can also search by product code or regulation number at the top of the tree. Always read the special controls if any exist for your device — it broadens your search and sharpens pre-kickoff research.
What can you do from the regulations tree view?
Browse product codes and regulation numbers, read the identification text and special controls, browse sibling product codes, open device PDFs on the right, and search by product code or regulation number at the top of the tree.
8. Chart view
Click Show Chart and segment by regulation number (or product code) to see which regulations dominate your result set. Clicking a regulation takes you into the regulations tree. Great for spotting that most matches are, say, hardware laparoscopic devices — a cue to go back and filter.
How do you see which regulations dominate a search result set?
Click "Show Chart" and segment by Regulation Number. Clicking a regulation takes you to the regulations tree.
9. The predicate graph
Open the Predicates tab for a family-tree view of predicate relationships. Click a node to trace its parents and children; selections from search carry over pre-selected. Commonly predicated devices are worth reading — a lot of people predicated them for a reason. The visual lineage is also handy on client calls, e.g. to show how a predicate family evolved and justify why your predicate still holds.
In the predicate graph, why are commonly predicated devices worth reading?
A lot of people predicated them for a reason. Clicking a node traces parents and children, and selections from search carry over pre-selected.
10. Embeddings: the galaxy map
The Embeddings tab plots every matching document in a 2-D "galaxy map" where semantically similar devices cluster together. Hover or click clusters to explore, and let AI label the clusters for you. Embeddings beat product codes for grouping: two devices can carry different product codes (LLZ vs. QIH) yet do the same thing — the embedding captures the meaning of the intended use and device story. This is also exactly how retrieval-augmented generation (RAG) works under the hood, and it makes a great visual on client calls.
Try it yourself
Head to the search page and work through a few of these AI/ML fuzzy searches to build intuition: perivascular fat on CT · aortic valve calcification opportunistic screening on noncontrast CT · breast cancer prediction on digital pathology slides · autism detection · gestational age prediction · a hearing aid that can also detect a pulse · foundation model based analysis of ECG · large language models · penetration test. Watch how the relevance scores, intended use, and AI Performance tables tell you when results stop being meaningful.