The CRIT-LINE MONITOR III, (CLM III), is a non-invasive hematocrit, oxygen saturation and percent change in blood volume monitor used in the treatment of hemodialysis patients. In addition, the CLM III estimates access recirculation and access blood flow in hemodialysis patients.
Device Story
CLM III is a microprocessor-based monitor used in hemodialysis clinics by technicians. It connects to an In-Line Diagnostics blood chamber integrated into the dialysis tubing circuit. The device measures real-time hematocrit, oxygen saturation, and blood volume as blood passes through the chamber. To estimate Access Blood Flow (ABF), the technician performs a specific protocol involving ultrafiltration rate adjustments and temporary reversal of arterial and venous lines; hematocrit data is collected at four-minute intervals. These measurements are processed via an external calculator or spreadsheet using a specific formula to derive the ABF value. The output assists clinicians in managing fluid removal rates to prevent dialysis-related symptoms like nausea, cramping, and vomiting, and provides an indicator of dialysis access site condition (deterioration or blockage) without requiring invasive methods like X-ray.
Clinical Evidence
Two clinical studies (March/April 1998) involving 44 total patients (30 at University of Utah/Veterans Hospital, 14 at Victoria Hospital South). Protocol involved gathering hematocrit data during dialysis with arterial/venous line reversal. CLM III-derived ABF values were compared against Transonic HD01 measurements. Results showed a correlation coefficient of ≥ 0.90, meeting the pre-defined criteria for substantial equivalence.
Technological Characteristics
Microprocessor-based monitor with chip select logic, serial communication, timing, and watchdog circuits. Uses an In-Line Diagnostics blood chamber sensor. Connectivity: integrated into dialysis tubing circuit. Software: same as K972470; ABF calculation performed via external calculator/spreadsheet using real-time hematocrit data. No hardware or software changes required for ABF feature.
Indications for Use
Indicated for hemodialysis patients to monitor hematocrit, oxygen saturation, percent change in blood volume, access recirculation, and access blood flow.
Regulatory Classification
Identification
A hemodialysis system and accessories is a device that is used as an artificial kidney system for the treatment of patients with renal failure or toxemic conditions and that consists of an extracorporeal blood system, a conventional dialyzer, a dialysate delivery system, and accessories. Blood from a patient flows through the tubing of the extracorporeal blood system and accessories to the blood compartment of the dialyzer, then returns through further tubing of the extracorporeal blood system to the patient. The dialyzer has two compartments that are separated by a semipermeable membrane. While the blood is in the blood compartment, undesirable substances in the blood pass through the semipermeable membrane into the dialysate in the dialysate compartment. The dialysate delivery system controls and monitors the dialysate circulating through the dialysate compartment of the dialyzer.(1) The extracorporeal blood system and accessories consists of tubing, pumps, pressure monitors, air foam or bubble detectors, and alarms to keep blood moving safely from the blood access device and accessories for hemodialysis (§ 876.5540) to the blood compartment of the dialyzer and back to the patient. (2) The conventional dialyzer allows a transfer of water and solutes between the blood and the dialysate through the semipermeable membrane. The semipermeable membrane of the conventional dialyzer has a sufficiently low permeability to water that an ultrafiltration controller is not required to prevent excessive loss of water from the patient's blood. This conventional dialyzer does not include hemodialyzers with the disposable inserts (Kiil type) (§ 876.5830) or dialyzers of high permeability (§ 876.5860). (3) The dialysate delivery system consists of mechanisms that monitor and control the temperature, conductivity, flow rate, and pressure of the dialysate and circulates dialysate through the dialysate compartment of the dialyzer. The dialysate delivery system includes the dialysate concentrate for hemodialysis (liquid or powder) and alarms to indicate abnormal dialysate conditions. This dialysate delivery system does not include the sorbent regenerated dialysate delivery system for hemodialysis (§ 876.5600), the dialysate delivery system of the peritoneal dialysis system and accessories (§ 876.5630), or the controlled dialysate delivery system of the high permeability hemodialysis system § 876.5860). (4) Remote accessories to the hemodialysis system include the unpowered dialysis chair without a scale, the powered dialysis chair without a scale, the dialyzer holder set, dialysis tie gun and ties, and hemodialysis start/stop tray.
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Image /page/0/Picture/1 description: The image shows the date "OCT - 9 1998" at the top left. Below the date is the text "-IN-LINE" in bold, followed by a logo with the text "CRIT-LINE" on top. To the right of the logo is the text "DIAGNOSTICS" in bold with a trademark symbol. The text and logo appear to be part of a company or product name.
# 510(k) SUMMARY
## Submitter's Information 1.
Matthew L. Haynie In-Line Diagnostics (IDC) 117 West 200 South Farmington, UT 84025 Tel: 801-451-9000 Fax: 801-451-9007
# 510(k) Summary Prepared By:
Same as above
## 2. Date 510(k) Summary Prepared:
July 7, 1998
## 3. Name of Device:
CRIT-LINE MONITOR III (CLM III): Permission to claim additional feature of Access Blood Flow (ABF).
## Common Name:
Non-invasive hematocrit, blood volume and oxygen saturation monitor
## Classification Name:
Hemodialysis system monitor accessory
## Identification of legally marketed device which the submitter claims 4. equivalence:
The ABF values, which have been calculated from of the hematocrit data measured by the CLM III, have been found to be substantially equivalent to the values measured by the Transonic HD01 Monitor (#K960817) which is currently being marketed by Transonic Systems, Inc.
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## Description of the Subject Devices: 5.
The CLM III consists of a state-of-the-art microprocessor which has all of the chip select logic, serial communication, timing and watchdog circuits incorporated within it. The CLM III is used in conjunction with the In-Line Diagnostics Blood Chamber. The blood chamber is connected to and becomes part of the dialysis tubing circuit. The sensor from the CLM III is connected to the blood chamber which reads critical blood parameters as blood passes through the blood chamber.
## Intended use of the Subject Device: 6.
The CLM III is used as a non-invasive hematocrit, oxygen saturation and blood volume monitor. These parameters are measured in real time for application in the treatment of dialysis patients with the intended purpose of providing a more effective treatment for the dialysis patient. Based on the data that the monitors provide, the dialysis technician increases and decreases the rate at which fluid is removed from the patient's blood in order to maximize fluid removal without the patient experiencing the common symptoms of dialysis which include nausea, cramping and vomiting.
Recently, it has come to the attention of In-Line Diagnostics (IDC), that the CLM III can also be used to measure Access Blood Flow (ABF) which is the rate at which blood is flowing through the dialysis patient's access site. This measurement can be made without any software or hardware changes to the current device. ABF is a good indicator of a site's condition (i.e. how deteriorated or blocked that site has become). Providing a quick easy method of determining ABF would eliminate the need for more expensive, time-consuming methods such as X-ray.
It is IDC's intention to show in this submission that the ABF values gathered by the CLM III technique are substantially equivalent to the values gathered by the Transonic HD01 Monitor and as a result be allowed to claim ABF as an additional feature to the CLM III.
#### 7. Technological Characteristics of the Subject Devices:
As stated above, the CLM III can be used to measure ABF without any hardware or software changes. ABF values are calculated by an independent means (i.e. calculator or spreadsheet) from real time hematocrit measurements which are measured by the CLM III. As a result, the technological characteristics (both hardware and software) are exactly the same as in the previous submission of the CLM III (#K972470).
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## Discussion of Clinical Tests Performed: 8.
The CLM III ABF values were compared to the Transonic HD01 ABF values during two separate studies in March and April 1998. One study took place on 30 patients at the University of Utah Dialysis Program and Veterans Hospital in Salt Lake City, Utah and the other study took place on 14 patients at Victoria Hospital South in London, Ontario Canada.
During the study, a formal protocol was followed in which hematocrit data was gathered during normal dialysis sessions. During the session, ultrafiltration rates were adjusted and the arterial and venous lines were temporarily reversed. During this time, hematocrit values were gathered at four-minute intervals. These hematocrit values were then calculated into a formula (i.e. with a calculator or spreadsheet) to calculate an AFB value. This ABF value was then compared to the Transonic HD01 ABF value which was measured at the conclusion of the four-minute measurements previously described.
When the CLM III ABF data was compared to the Transonic HD01 data, it was determined that the criteria for the CLM III values to be considered as substantially equivalent was a correlation coefficient value near 1 (i.e. . 90 or greater).
The results from the two rests indicate that the above described criteria were met.
## 9. Conclusions
In conclusion, based on comparison with the legally marketed Transonic HD01 Monitor, the subject CLM III is safe and effective and performs as well as the legally marketed Transonic HD01 Monitor.
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Image /page/3/Picture/0 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of two main elements: the department's name arranged in a circular fashion around the left side and a stylized emblem on the right. The emblem features a series of curved lines that resemble an abstract representation of an eagle or a similar bird-like figure.
Food and Druq Administration 9200 Corporate Boulevard Rockville MD 20850
Mr. Matthew L. Havnie Director of Quality Assurance/Regulatory Affairs In-Line Diagnostics Corporation 117 West 200 South P.O. Box 685 Farmington, Utah 84025-0685
Re: K982412 CRIT-LINE III Monitor (for Access Blood Flow in Hemodialysis) Dated: July 7, 1998 Received: July 13, 1998 Regulatory Class: II 21 CFR 876.5820/Procode: 78 MQS
Dear Mr. Haynie:
OCT - 9 1998
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 of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, against misbranding and adulteration.
If your device is classified (see above) into either class II (Premarket Approval), 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 895. A substantially equivalent determination assumes compliance with the Current Good Manufacturing Practice requirements, as set forth in the Quality System Regulation (OS) 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 action. In addition. FDA may publish further announcements concerning your device in the Federal Register. this response to your premarket notification submission does not affect any obligation you might have under sections 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.
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 additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4613. 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" (21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its Internet address "http://www.fda.gov/cdrh/dsmaldsmamain.html".
Sincerely yours.
Lillian Yin, Ph.D.
Director, Division of Reproductive, Abdominal, Ear, Nose and Throat and Radiological Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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510(k) Number (if known): K982412
Device Name: CRIT-LINE III MONITOR with additional feature - Estimation of Access Blood Flow
Indications for Use:
The CRIT-LINE MONITOR III, (CLM III), is a non-invasive hematocrit, oxygen saturation and percent change in blood volume monitor used in the treatment of hemodialysis patients. In addition, the CLM III estimates access recirculation and access blood flow in hemodialysis patients.
(PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NEEDED)
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Concurrence of CDRH, Office of Device Evaluation (ODE)
Prescription for Use _ (Per 21 CFR 801.109)
OR
Over the Counter Use__________________________________________________________________________________________________________________________________________________________
(Optional Format 1-2-96)
Daniel A. Segner
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(Division Sign-Off) Division of Reproductive, Abdominal, ENT, and Radiological Devices 510(k) Number _
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.
