K981769 · Elan Pharma, Inc. · CEO · Jun 29, 1998 · Clinical Chemistry
Device Facts
Record ID
K981769
Device Name
HICHEM PHOSPHORUS REAGENT KIT
Applicant
Elan Pharma, Inc.
Product Code
CEO · Clinical Chemistry
Decision Date
Jun 29, 1998
Decision
SESE
Submission Type
Traditional
Regulation
21 CFR 862.1580
Device Class
Class 1
Indications for Use
HiChem Phosphorus Reagent is intended for the quantitative determination of inorganic phosphorus in serum, plasma and urine for the diagnosis and treatment of various disorders including parathyroid gland and kidney diseases, and vitamin D imbalance. This reagent is intended to be used in a professional setting or by trained personnel and is not intended for home use.
Device Story
HiChem Phosphorus Reagent is an in vitro diagnostic chemical reagent kit. It utilizes a molybdate-based colorimetric method to measure inorganic phosphorus in serum, plasma, or urine samples. The reagent reacts with phosphorus in an acidic solution to form a phosphomolybdate complex; the resulting increase in absorbance at 340 nm is measured via spectrophotometry. The device is intended for use in clinical laboratories by trained personnel using manual spectrophotometers or automated clinical analyzers (e.g., Hitachi 704, Beckman SYNCHRON CX Systems). Healthcare providers use the resulting phosphorus concentration values to diagnose and monitor metabolic, parathyroid, and renal disorders. The reagent provides a standardized, automated, or manual method for quantitative analysis, facilitating clinical decision-making regarding patient treatment plans.
Clinical Evidence
Bench testing only. Performance validated via linearity studies (0.1–15 mgP/dL manual; 1.0–12.0 mgP/dL automated), precision studies (within-run and total SD), and method comparison studies. Serum/plasma/urine recoveries compared to predicate reagents using least squares regression (r2 values 0.972–0.999). Sensitivity limits documented via repetitive assay of diluted serum controls. Chemical additive interference (heparin) evaluated with bias <0.15 mgP/dL.
Technological Characteristics
Colorimetric reagent kit; molybdate-based chemistry; acidic solution; spectrophotometric detection at 340 nm. Compatible with manual spectrophotometers and automated clinical analyzers (Hitachi 704, Beckman SYNCHRON CX). Reagent stability validated for 30 days on-board; calibration stability validated for 14-60 days. No electronic components; software-independent reagent chemistry.
Indications for Use
Indicated for quantitative determination of inorganic phosphorus in serum, plasma, and urine to aid diagnosis/treatment of parathyroid gland disease, kidney disease, and vitamin D imbalance. For professional use only; not for home use.
Regulatory Classification
Identification
A phosphorus (inorganic) test system is a device intended to measure inorganic phosphorus in serum, plasma, and urine. Measurements of phosphorus (inorganic) are used in the diagnosis and treatment of various disorders, including parathyroid gland and kidney diseases, and vitamin D imbalance.
Predicate Devices
BMD Phosphorus Reagent (product no. 857427)
Beckman SYNCHRON Systems Phosphorus Reagent (product no. 465145)
Submission Summary (Full Text)
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Image /page/0/Picture/1 description: The image shows the logo for HiChem Diagnostics. The logo consists of a black circle at the top, followed by the words "Smart Solutions" in a smaller font. Below that is the word "HiChem" in a bold, sans-serif font, and below that is the word "DIAGNOSTICS" in a smaller, sans-serif font.
K981769
## SUMMARY OF 510(K) SAFETY AND EFFECTIVENESS INFORMATION
This summary of 510(k) safety and effectiveness information is being submitted in accordance with the requirements of SMDA 1990 and 21 CFR 807.92.
HiChem Phosphorus Reagent is intended for the quanitiation of inorganic phosphorus in serum, plasma and urine. Measurements of inorganic phosphorus are used in the diagnosis and treatment of various disorders, including parathyroid gland and kidney diseases, and vitamin D imbalance.
The HiChem Phosphorus Reagent determines phosphorus by its reaction with molybdate in an acidic solution to form a phosphomolybdate complex. The resulting increase in absorbance at 340 nm is proportional to the phosphorus concentration in the sample.
The HiChem Phosphorus Reagent is an adaptation of the method first described by Simonsen and is intended for use with manual spectrophotometers or clinical analyzers which can automate the required manipulations.
The HiChem Phosphorus Reagent is substantially equivalent to the BMD® Phosphorus Reagent, product no. 857427, manufactured by Boehringer Mannheim Corp., Indianapolis, IN., and the Beckman® SYNCHRON® Systems Phosphorus Reagent, product no. 465145, manufactured by Beckman® Instruments, Brea, CA. All three reagents support the same intended use and produce equivalent results with the same clinical purpose. In addition, they are all based on the same methodology which determines inorganic phosphorus through the colorimeric measurement of the phosphomolybdate complex produced in an acidic reagent.
The effectiveness of the manual procedure is shown by the recovery of linearity standards, the precision of control recoveries, the comparison of serum, plasma and urine recoveries to the BMD® Phosphorus Reagent and the validation of the chemical additives and sensitivity claims.
The recovery of inorganic phosphorus using HiChem Phosphorus Reagent as a manual procedure is linear between 0.1 and 15 mgP/dL as shown by the recovery of linearity standards which span the claimed linear range. Regression statistics are shown below.
(HiChem Recoveries) = 0.1 mgP/dL + 1.004 × (Standard Conc.), r2 = 1.000, sv.x = 0.10 mgP/dL, df = 23
Precision, demonstrated by replicate assay of urine pools and commercially available control sera, is shown below.
| Specimen | n | mean | within-run SD | total SD |
|-----------------|----|----------------|---------------|-------------|
| Serum control 1 | 30 | 2.09 mgP/dL/L | 0.02 mgP/dL | 0.03 mgP/dL |
| Serum control 2 | 30 | 6.17 mgP/dL/L | 0.07 mgP/dL | 0.08 mgP/dL |
| Urine Pool 1 | 30 | 2.10 mgP/dL/L | 0.00 mgP/dL | 0.00 mgP/dL |
| Urine Pool 2 | 30 | 10.43 mgP/dL/L | 0.06 mgP/dL | 0.07 mgP/dL |
Phosphorus recoveries of 95 mixed serum and plasma specimens and 44 urine specimens are compared between the HiChem manual procedure and the BMD® Phosphorus Reagent on the Hitachi® 704. Least squares regression statistics are shown below.
Serum/ Plasma Comparisons: (HiChem Results) = -0.1 mgP/dL + 0.982 × (BMD® Results), sy.x = 0.14 mgP/dL r2 = 0.985. Urine Comparisons: sv.x = 0.11 mgP/dL (HiChem Results) = 0.2 mgP/dL + 0.966 x (BMD® Results), r2 = 0.999.
The use of sodium, lithium and ammonium heparin are shown to be acceptable chemical additives by comparison of spiked and unspiked serum pools. In all cases, the biases produced by the additive were less than 0.1 mgP/dL.
510(k) Notification, HiChem Phosphorus Reagent Kit, p 95
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The sensitivity claim of 0.1 mgP/dL is documented through the repetitive assay of a diluted serum control. The observed sensitivity limit, calculated as three standard deviations of a 30 replicate within run precision study, is 0.05 mgP/dL and less than the claim of 0.1 mgP/dL.
The effectiveness of the HiChem secondary reagent application for the Beckman® SYNCHRON CX® Systems is shown by the recovery of linearity standards, the precision of control recovery of serum controls over both the calibration stability and on-board stability claims, the validation of the chemical additives and the comparison of patient specimen recoveries to the Beckman® SYNCHRON® Systems Phosphorus Reagent.
The recovery of inorganic phosphorus using the HiChem PO4 Reagent in the SYNCHRON CX® Systems is linear from at least 1.0 mgP/dL to 12.0 mgP/dL as shown by the recovery of six linearity standards which span the claimed linear range. Regression statistics are shown below.
sy.x = 0.08 mgP/dL, df = 35 (HiChem Recoveries) = -0.2 mgP/dL + 0.971 × (Standard Conc.), r2 = 1.000,
Precision, demonstrated by replicate assay of urine pools and commercially available control sera, is shown below.
| Specimen | n | mean | within-run SD | total SD |
|-----------------|----|---------------|---------------|-------------|
| Serum control 1 | 60 | 1.89 mgP/dL/L | 0.08 mgP/dL | 0.09 mgP/dL |
| Serum control 2 | 60 | 4.13 mgP/dL/L | 0.11 mgP/dL | 0.11 mgP/dL |
| Serum control 3 | 60 | 6.44 mgP/dL/L | 0.10 mgP/dL | 0.10 mgP/dL |
| Urine Pool 1 | 60 | 2.75 mgP/dL/L | 0.11 mgP/dL | 0.11 mgP/dL |
| Urine Pool 2 | 60 | 9.46 mgP/dL/L | 0.08 mgP/dL | 0.13 mgP/dL |
Phosphorus recoveries of 153 mixed serum and plasma specimens are compared between the HiChem and Beckman® PO4 Reagents on the SYNCHRON CX® Systems. Least squares regression statistics are shown below.
Serum/ Plasma Comparisons:
r2 = 0.972, (HiChem Results) = - 0.4 mgP/dL + 1.040 x (BMD® Results), sv.x = 0.15 mgP/dL Urine Comparisons: (HiChem Results) = - 0.2 mgP/dL + 1.001 x (BMD® Results), r2 = 0.996, sv.x = 0.15 mgP/dL
The use of sodium, lithium and ammonium heparin are shown to be acceptable chemical additives by comparison of spiked and unspiked serum pools. In all cases, the observed biases were less than 0.15 mgP/dL.
The sensitivity claim of 1.0 mgP/dL is documented through the repetitive assay of a diluted serum control. The observed sensitivity limit, calculated as three standard deviations of a 30 replicate within run precision study, is 0.3 mgP/dL and is well below the claimed limit of 0.1 mgP/dL.
The 14 day onboard calibration stability, the 60 day within lot callbration stability and the 30 day on board reagent stability claims are documented through the assay of serum controls and urine pools over the claimed periods. In all cases, estimates of imprecision of phosphorus recoveries over the claimed intervals are less than the greater of 0.3 mgP/dL or 3.%, which is the manufacturer's total precision claim for the SYNCHRON® Analyzer.
The HiChem Phosphorus Reagent is shown to be safe and effective and substantially equivalent to the BMD® Phosphorus Reagent, product no. 857427, manufactured by Boehringer Mannheim Corp., Indianapolis, IN., and the Beckman® SYNCHRON® Systems PO4 Reagent, product no. 465145, manufactured by Beckman® Instruments, Brea, CA.
Wynn Storkey
Stocking Manager of Regulatory Affairs HiChem Diagnostics
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Image /page/2/Picture/2 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo features a stylized eagle with three bars representing its wings. The text "DEPARTMENT OF HEALTH & HUMAN SERVICES • USA" is arranged in a circular pattern around the eagle.
Food and Drug Administration 2098 Gaither Road Rockville MD 20850
JUN 29 1998
Wynn Stocking . Manager, Regulatory Affairs HiChem Diagnostics 231 North Puente Street 92821 Brea, California
K981769 Re : HiChem Phosphorus Reagent Requlatory Class: I Product Code: CEO Dated: May 18, 1998 Received: May 19, 1998
Dear Mr. Stocking:
We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to 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). You may, therefore, market the device, subject to the general controls provisions The general controls provisions of the Act 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 (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Requlations, Title 21, Parts 800 to 895. ਉ substantially equivalent determination assumes compliance with the Current Good Manufacturing Practice requirements, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic QS inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory In addition, FDA may publish further announcements action. concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.
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Page 2
This letter will allow you to begin marketing your device as Inis lected will arrow you on researce notification. The FDA described in your 510(K) prematics of your device to a legally marketed predicate device results in a classification for your marketed predicate device to proceed to the market. device and thus, permice your device for your device on our labeling of If you desire specific advice for your additionally 809.10 for in vitro diagnostic devices), please contact the Office of Villo diagnoseic acriose/788. Additionally, for questions on Compilance ac (501) 331 issim 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" (21 CFR 807.97) . Other general information on your responsibilities under the Act may be Information on Joanivision of Small Manufacturers Assistance obcarned from the number (800) 638-2041 or (301) 443-6597 or at its internet address "dsmo@fdadr.cdrh.fda.gov".
Sincerely yours,
Steven Autman
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
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K981769/A
Page 1 of 1
510(k) Number (if known): K981769
Device Name:
HiChem Phosphorus Reagent Kit
Indications For Use:
HiChem Phosphorus Reagent is intended for the quantitative determination of inorganic phosphorus in serum, plasma and urine for the diagnosis and treatment of various disorders including parathyroid gland and kidney diseases, and vitamin D imbalance.
This reagent is intended to be used in a professional setting or by trained personnel and is not intended for home use.
Respectfully,
Wynn Stocking
Wynh Stocking Regulatory Affairs Manager HiChem Diagnostics
2 June, 1998
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Prescription Use
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8K-6
Two short videos show you everything — or skip straight to the written tutorial if you'd rather read. You can reopen this any time from the Tutorial button in the top bar.
Part 1 — Search, results, and everyday workflows 16 min
Part 2 — Embeddings: the galaxy map 3 min
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.