(65 days)
Not Found
No
The summary describes a standard immunoassay for measuring testosterone levels and does not mention any AI or ML components. The performance studies are based on traditional analytical methods.
No.
This device is an in vitro diagnostic (IVD) assay designed to quantitatively measure total testosterone levels for diagnostic purposes, not to provide therapy.
Yes
The Access Testosterone assay is used for the quantitative determination of total testosterone levels, and these measurements "are used in the diagnosis and treatment of disorders involving the male sex hormones." This clearly indicates its role in diagnosing conditions.
No
The device description explicitly states it consists of a reagent pack and calibrators, which are physical components, and is designed for use with a specific hardware analyzer (Dxl 9000 Access Immunoassay Analyzer). This indicates it is not a software-only device.
Yes, this device is an IVD (In Vitro Diagnostic).
Here's why:
- Intended Use: The intended use explicitly states "for the quantitative determination of total testosterone levels in human serum and plasma". This indicates the device is used to test samples taken from the human body (in vitro) to provide diagnostic information.
- Indications for Use: The indications for use describe how the measurement of testosterone is used in the "diagnosis and treatment of disorders". This further confirms its diagnostic purpose.
- Device Description: The description details a "paramagnetic particle, chemiluminescent immunoassay" and mentions "reagent pack and calibrators", which are typical components of in vitro diagnostic assays. It also specifies use with an "Immunoassay Analyzer in a clinical laboratory setting", which is where IVD tests are performed.
- Performance Studies: The inclusion of performance studies like Method Comparison, Linearity, Imprecision, LoB, LoD, and LoQ are standard for demonstrating the analytical performance of an IVD.
- Predicate Device: The mention of a "Predicate Device(s)" with a K number (K001935; Access Testosterone assay) strongly suggests this is a submission for a device that is substantially equivalent to a previously cleared IVD.
All these elements align with the definition and characteristics of an In Vitro Diagnostic device.
N/A
Intended Use / Indications for Use
The Access Testosterone assay is a paramagnetic particle, chemiluminescent immunoassay for the quantitative determination of total testosterone levels in human serum and plasma using the Access Immunoassay Systems.
Measurement of testosterone are used in the diagnosis and treatment of disorders involving the male sex hormones (androgens), including primary and secondary hypogonadism, delayed or precocious puberty, impotence in males and, in females hirsutism (excessive hair) and virilization (masculinization) due to tumors, polycystic ovaries, and adrenogenital syndromes.
Product codes
CDZ
Device Description
The Access Testosterone assay is a competitive binding immunoenzymatic assay. The Access Testosterone assay consists of the reagent pack and calibrators. Other items needed to run the assay include substrate and wash buffer. The Access Testosterone assay reagent pack, Access Testosterone assay calibrators, along with the UniCel Dxl wash buffer II are designed for use with the Dxl 9000 Access Immunoassay Analyzer in a clinical laboratory setting.
Mentions image processing
Not Found
Mentions AI, DNN, or ML
Not Found
Input Imaging Modality
Not Found
Anatomical Site
Not Found
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
Not Found
Summary of Performance Studies
Method comparison study was performed to compare the Access Testosterone assay on Dxl 9000 Access Immunoassay Analyzer to a previously cleared system. Method comparison and bias estimation experiments were designed in accordance with the CLSI EP09c-A3 "Method Procedure Comparison and Bias Estimation Using Patient Samples; Approved Guideline – Third Edition". A total of one hundred and eight (108) serum samples were evaluated in the method comparison study. The results of the method comparison study met the acceptance criteria of R2 ≥ 0.90 and slope of 1.00 ± 0.14 and support the equivalence of the Access Testosterone assay on Dxl 9000 Access Immunoassay Analyzer to the Access Testosterone assay on the Access 2 instrument.
Linearity: A verification study was performed to evaluate the linearity of the Access Testosterone assay on the Dxl 9000 Access Immunoassay Analyzer based on CLSI EP06-Ed2 "Evaluation of the Linearity of Quantitative Measurement Procedures: A Statistical Approach; Approved Guideline". The low sample was a native serum sample. The high sample was created by spiking a native serum sample with Testosterone antigen. All other samples tested were mixtures of the low and high sample. The Access Testosterone assay is linear on the Dxl 9000 Access Immunoassay Analyzer throughout the analytical measuring interval of 0.4 - 16.0 ng/mL.
Imprecision: Repeatability (within-run) and within-laboratory (total) precision studies were designed in accordance with the CLSI Guideline EP05-A3 "Evaluation of Precision of Quantitative Measurement Procedures: Approved Guideline - Third Edition". The study was run on three Dxl 9000 Access Immunoassay Analyzers, three reagent lots, and three calibrator lots. Six (6) serum samples with Testosterone concentrations spanning the range of the assay were each tested in replicates of two (2) per run with two (2) runs per day with a minimum of 20 days on each instrument and reagent lot combination. Two (2) samples were native serum samples from individual donors, three (3) were native pooled serum samples and one (1) sample was prepared by spiking native serum samples with an antigen to achieve adequate coverage at the high end of the analytical range. The assay was designed to have within-laboratory imprecision as listed below:
• ≤ 0.14 ng/mL (0.49 nmol/L) SD at concentrations ≤ 1.4 ng/mL (4.9 nmol/L)
• ≤ 10.0% CV at concentrations > 1.4 ng/mL (4.9 nmol/L)
LoB, LoD and LoQ: Limit of Blank (LoB), Limit of Detection (LoD), and Limit of Quantitation (LoQ) studies were designed from the CLSI quideline EP17-A2 "Evaluation of Detection Capability for Clinical Laboratory Measurement Procedures Approved Guideline - Second Edition". Four blank samples (Matrix lacking Testosterone antigen) were used for LoB determination. For estimation of LoD, seven serum samples containing low levels of Testosterone analyte were measured. For estimation of LoQ, 12 serum samples containing low levels of Testosterone analyte were measured. The LoB study included multiple reagent lots and 3 Dxl 9000 Access Immunoassay Analyzers over a minimum of 3 days. The LoD and LoQ studies included multiple reagent lots and 3 Dxl 9000 Access Immunoassay Analyzers over a minimum of 5 days. The assay has an LoB of 0.2 ng/mL (0.7 nmol/L), LoD of 0.4 ng/mL (1.39 nmol/L) and 20% Within-Laboratory CV LoQ of 0.4 ng/mL (1.39 nmol/L).
Key Metrics
Method Comparison:
N: 108
Concentration Range (ng/mL): 0.48, 14
Slope: 0.95
Slope 95% CI: 0.93, 0.98
Intercept: 0.028
Intercept 95% CI: -0.015, 0.071
Correlation Coefficient R2: 0.98
Imprecision (for Sample 1, N=88, Mean=0.71 ng/mL):
Repeatability (Within-run) SD: 0.03, %CV: 3.6
Between-run SD: 0.02, %CV: 3.4
Between-day SD: 0.02, %CV: 3.4
Within-Laboratory SD: 0.04, %CV: 6.0
Imprecision (for Sample 2, N=88, Mean=2.0 ng/mL):
Repeatability (Within-run) SD: 0.05, %CV: 2.6
Between-run SD: 0.05, %CV: 2.6
Between-day SD: 0.05, %CV: 2.3
Within-Laboratory SD: 0.09, %CV: 4.4
Imprecision (for Sample 3, N=88, Mean=4.8 ng/mL):
Repeatability (Within-run) SD: 0.09, %CV: 1.9
Between-run SD: 0.08, %CV: 1.7
Between-day SD: 0.14, %CV: 3.0
Within-Laboratory SD: 0.19, %CV: 3.9
Imprecision (for Sample 4, N=88, Mean=7.1 ng/mL):
Repeatability (Within-run) SD: 0.13, %CV: 1.8
Between-run SD: 0.09, %CV: 1.2
Between-day SD: 0.29, %CV: 4.0
Within-Laboratory SD: 0.33, %CV: 4.6
Imprecision (for Sample 5, N=88, Mean=8.6 ng/mL):
Repeatability (Within-run) SD: 0.18, %CV: 2.1
Between-run SD: 0.25, %CV: 2.9
Between-day SD: 0.40, %CV: 4.7
Within-Laboratory SD: 0.51, %CV: 5.9
Imprecision (for Sample 6, N=88, Mean=14 ng/mL):
Repeatability (Within-run) SD: 0.3, %CV: 2.2
Between-run SD: 0.2, %CV: 1.6
Between-day SD: 1.0, %CV: 7.3
Within-Laboratory SD: 1.1, %CV: 7.8
LoB: 0.2 ng/mL (0.7 nmol/L)
LoD: 0.4 ng/mL (1.39 nmol/L)
20% Within-Laboratory CV LoQ: 0.4 ng/mL (1.39 nmol/L)
Predicate Device(s)
Reference Device(s)
Not Found
Predetermined Change Control Plan (PCCP) - All Relevant Information
Not Found
§ 862.1680 Testosterone test system.
(a)
Identification. A testosterone test system is a device intended to measure testosterone (a male sex hormone) in serum, plasma, and urine. Measurement of testosterone are used in the diagnosis and treatment of disorders involving the male sex hormones (androgens), including primary and secondary hypogonadism, delayed or precocious puberty, impotence in males and, in females hirsutism (excessive hair) and virilization (masculinization) due to tumors, polycystic ovaries, and adrenogenital syndromes.(b)
Classification. Class I.
0
Image /page/0/Picture/0 description: The image contains the logo of the U.S. Food and Drug Administration (FDA). The logo consists of two parts: the Department of Health & Human Services logo on the left and the FDA logo on the right. The FDA logo is in blue and includes the letters "FDA" followed by the words "U.S. FOOD & DRUG ADMINISTRATION" in a stacked format.
January 13, 2023
Beckman Coulter, Inc. Kuljeet Kaur Regulatory Affairs Manager 1000 Lake Hazeltine Drive Chaska, MN 55318
Re: K223405
Trade/Device Name: Access Testosterone Regulation Number: 21 CFR 862.1680 Regulation Name: Testosterone test system Regulatory Class: Class I, reserved Product Code: CDZ Dated: November 7, 2022 Received: November 9, 2022
Dear Kuljeet Kaur:
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. 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 located 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.
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
1
801 and Part 809); medical device reporting of medical device-related adverse events) (21 CFR 803) for devices or postmarketing safety reporting (21 CFR 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-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 4. Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 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-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.
For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/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-device-advice-comprehensive-regulatoryassistance/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,
Image /page/1/Figure/6 description: The image shows a digital signature. The signature is by Paula Caposino -S. The date of the signature is 2023.01.13 and the time is 17:18:55 -05'00'.
Paula Caposino, Ph.D. Acting Deputy Director Division of Chemistry and Toxicology Devices OHT7: Office of In Vitro Diagnostics Office of Product Evaluation and Quality Center for Devices and Radiological Health
Enclosure
2
Indications for Use
510(k) Number (if known) K223405
Device Name Access Testosterone
Indications for Use (Describe)
The Access Testosterone assay is a paramagnetic particle, chemiluminescent immunoassay for the quantitative determination of total testosterone levels in human serum and plasma using the Access Immunoassay Systems.
Measurement of testosterone are used in the diagnosis and treatment of disorders involving the male sex hormones (androgens), including primary and secondary hypogonadism, delayed or precocious puberty, impotence in males and, in females hirsutism (excessive hair) and virilization) due to tumors, polycystic ovaries, and adrenogenital syndromes.
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 Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff PRAStaff(@fda.hhs.gov
"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."
3
Image /page/3/Picture/0 description: The image shows the logo for Beckman Coulter. The logo consists of a red circle with two white curved lines inside, resembling a stylized wave or flow. To the right of the circle, the words "BECKMAN" and "COULTER" are written in bold, black, sans-serif font, with "BECKMAN" on the top line and "COULTER" on the bottom line.
Access Testosterone
510(k) Summary
This summary of 510(k) safety and effectiveness information is being submitted in accordance with the requirements of 21 CFR 807.92.
510(k) number: K223405
Submitted By:
Beckman Coulter, Inc. 1000 Lake Hazeltine Drive Chaska, MN 55318
Primary Contact:
Kuljeet Kaur, Ph.D. RAC Regulatory Affairs Manager 1000 Lake Hazeltine Drive Chaska, MN 55318 Phone: (952) 465-1914 Email: kkaur@beckman.com
Alternate Contact:
Kate Oelberg Senior Staff Regulatory and Quality Affairs Office Phone: (612) 431-7315 Email: kmoelberg@beckman.com
Date Prepared:
January 5, 2023
Common Name: Access Testosterone Assay Trade Name: Access Testosterone Classification Name: Testosterone test system Product Code: CDZ Classification Regulation: 21 CFR 862.1680
Predicate Device:
| Predicate Device | Manufacturer | 510(k) No. |
|---|---|---|
| Access Testosterone assay | Beckman Coulter, Inc. | K001935 |
4
Device Description:
The Access Testosterone assay is a competitive binding immunoenzymatic assay. The Access Testosterone assay consists of the reagent pack and calibrators. Other items needed to run the assay include substrate and wash buffer. The Access Testosterone assay reagent pack, Access Testosterone assay calibrators, along with the UniCel Dxl wash buffer II are designed for use with the Dxl 9000 Access Immunoassay Analyzer in a clinical laboratory setting.
Intended Use:
The Access Testosterone assay is a paramagnetic particle, chemiluminescent immunoassay for the quantitative determination of total testosterone levels in human serum and plasma using the Access Immunoassay Systems.
Measurement of testosterone are used in the diagnosis and treatment of disorders involving the male sex hormones (androgens), including primary and secondary hypogonadism, delayed or precocious puberty, impotence in males and, in females hirsutism (excessive hair) and virilization (masculinization) due to tumors, polycystic ovaries, and adrenogenital syndromes.
| Attribute/Characteristic | Predicate Access
Testosterone on Access
Immunoassay System | Access Testosterone
on Dxl 9000 Access
Immunoassay
Analyzer |
|-------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------|
| Intended Use/Indications
for Use | The Access Testosterone assay
is a paramagnetic particle,
chemiluminescent immunoassay
for the quantitative determination
of total testosterone levels in
human serum and plasma using
the Access Immunoassay
Systems. | Same |
| Analyte Measured | Testosterone | Same |
| Standardization | USP Reference Material | Same |
| Technology | One-step competitive binding | Same |
Comparison to the Predicate
5
| Attribute/Characteristic | Predicate Access
Testosterone on Access
Immunoassay System | Access Testosterone
on Dxl 9000 Access
Immunoassay Analyzer |
|-------------------------------------------|------------------------------------------------------------------|-------------------------------------------------------------------|
| Format | Chemiluminescent | Same |
| Method | Automated | Same |
| Calibration | Utilizes a stored calibration curve | Same |
| Traceability | USP reference material | Same |
| Sample Type | Serum, plasma (heparin) | Same |
| Stability | Stable at 2 to 10°C for 28 days
after initial use | Same |
| Reagent Pack formulation
and packaging | Access Reagent Pack
formulation and packaging. | Same |
| Measuring Range | 0.1 – 16.0 ng/mL | 0.4 – 16.0 ng/mL |
| Instrument | Access Immunoassay system | Dxl 9000 Access
Immunoassay Analyzer |
| Substrate | Access Substrate | Lumi-Phos PRO substrate |
Summary of Studies:
Method Comparison: Method comparison study was performed to compare the Access Testosterone assay on Dxl 9000 Access Immunoassay Analyzer to a previously cleared system. Method comparison and bias estimation experiments were designed in accordance with the CLSI EP09c-A3 "Method Procedure Comparison and Bias Estimation Using Patient Samples; Approved Guideline – Third Edition". A total of one hundred and eight (108) serum samples were evaluated in the method comparison study. The results of the method comparison study met the acceptance criteria of R2 ≥ 0.90 and slope of 1.00 ± 0.14 and support the equivalence of the Access Testosterone assay on Dxl 9000 Access Immunoassay Analyzer to the Access Testosterone assay on the Access 2 instrument.
| N | Concentration
Range (ng/mL) | Slope | Slope
95% CI | Intercept | Intercept
95% CI | Correlation
Coefficient R2 |
|-----|--------------------------------|-------|-----------------|-----------|---------------------|-------------------------------|
| 108 | 0.48, 14 | 0.95 | 0.93, 0.98 | 0.028 | -0.015,
0.071 | 0.98 |
6
Linearity: A verification study was performed to evaluate the linearity of the Access Testosterone assay on the Dxl 9000 Access Immunoassay Analyzer based on CLSI EP06-Ed2 "Evaluation of the Linearity of Quantitative Measurement Procedures: A Statistical Approach; Approved Guideline". The low sample was a native serum sample. The high sample was created by spiking a native serum sample with Testosterone antigen. All other samples tested were mixtures of the low and high sample. The Access Testosterone assay is linear on the Dxl 9000 Access Immunoassay Analyzer throughout the analytical measuring interval of 0.4 - 16.0 ng/mL.
Imprecision: Repeatability (within-run) and within-laboratory (total) precision studies were designed in accordance with the CLSI Guideline EP05-A3 "Evaluation of Precision of Quantitative Measurement Procedures: Approved Guideline - Third Edition". The study was run on three Dxl 9000 Access Immunoassay Analyzers, three reagent lots, and three calibrator lots. Six (6) serum samples with Testosterone concentrations spanning the range of the assay were each tested in replicates of two (2) per run with two (2) runs per day with a minimum of 20 days on each instrument and reagent lot combination. Two (2) samples were native serum samples from individual donors, three (3) were native pooled serum samples and one (1) sample was prepared by spiking native serum samples with an antigen to achieve adequate coverage at the high end of the analytical range. The assay was designed to have within-laboratory imprecision as listed below:
• ≤ 0.14 ng/mL (0.49 nmol/L) SD at concentrations ≤ 1.4 ng/mL (4.9 nmol/L)
• ≤ 10.0% CV at concentrations > 1.4 ng/mL (4.9 nmol/L)
| Concentration (ng/mL) | Repeatability
(Within-run) | Between-run | | Between-day | | Within-
Laboratory | | | | |
|-----------------------|-------------------------------|-------------|------|-------------|------|-----------------------|------|-----|------|-----|
| Sample | N | Mean | SD | %CV | SD | %CV | SD | %CV | SD | %CV |
| Sample 1 | 88 | 0.71 | 0.03 | 3.6 | 0.02 | 3.4 | 0.02 | 3.4 | 0.04 | 6.0 |
| Sample 2 | 88 | 2.0 | 0.05 | 2.6 | 0.05 | 2.6 | 0.05 | 2.3 | 0.09 | 4.4 |
| Sample 3 | 88 | 4.8 | 0.09 | 1.9 | 0.08 | 1.7 | 0.14 | 3.0 | 0.19 | 3.9 |
The results from a representative lot are as follows:
7
| Concentration (ng/mL) | | | Repeatability
(Within-run) | | Between-run | | Between-day | | Within-
Laboratory | |
|-----------------------|----|-----|-------------------------------|-----|-------------|-----|-------------|-----|-----------------------|-----|
| Sample 4 | 88 | 7.1 | 0.13 | 1.8 | 0.09 | 1.2 | 0.29 | 4.0 | 0.33 | 4.6 |
| Sample 5 | 88 | 8.6 | 0.18 | 2.1 | 0.25 | 2.9 | 0.40 | 4.7 | 0.51 | 5.9 |
| Sample 6 | 88 | 14 | 0.3 | 2.2 | 0.2 | 1.6 | 1.0 | 7.3 | 1.1 | 7.8 |
LoB, LoD and LoQ: Limit of Blank (LoB), Limit of Detection (LoD), and Limit of Quantitation (LoQ) studies were designed from the CLSI quideline EP17-A2 "Evaluation of Detection Capability for Clinical Laboratory Measurement Procedures Approved Guideline - Second Edition". Four blank samples (Matrix lacking Testosterone antigen) were used for LoB determination. For estimation of LoD, seven serum samples containing low levels of Testosterone analyte were measured. For estimation of LoQ, 12 serum samples containing low levels of Testosterone analyte were measured. The LoB study included multiple reagent lots and 3 Dxl 9000 Access Immunoassay Analyzers over a minimum of 3 days. The LoD and LoQ studies included multiple reagent lots and 3 Dxl 9000 Access Immunoassay Analyzers over a minimum of 5 days. The assay has an LoB of 0.2 ng/mL (0.7 nmol/L), LoD of 0.4 ng/mL (1.39 nmol/L) and 20% Within-Laboratory CV LoQ of 0.4 ng/mL (1.39 nmol/L).
Other claims: The claims for the analytical specificity, reference intervals, matrix comparison are being transferred from file K001935.
Substantial Equivalence Comparison Conclusion
Beckman Coulter's Testosterone Assay on the Dxl 9000 Access Immunoassay Analyzer is substantially equivalent to the Access Testosterone Assay on the Access Immunoassay System as demonstrated through the information and data provided in this submission. The performance testing presented in this submission provides evidence that the device is safe and effective in its intended use.