The ZOE™ Fluid Status Monitor is intended for use by qualified health care practitioners, under the direction of a physician, for the non-invasive monitoring and management of patients with fluid management problems in a variety of medically accepted clinical applications. Prescription Use (Per 21 CFR 801.109)
Device Story
ZOE™ Fluid Status Monitor is a non-invasive, battery-powered thoracic base impedance monitor. It applies minimal current to the patient to measure electrical impedance changes in the thorax corresponding to aortic blood flow and heartbeat. Base impedance (Zo) decreases with increased fluid and rises with decreased fluid. The device uses a proprietary algorithm to calculate Zo values. It is intended for use by qualified healthcare practitioners under physician direction in clinical settings. Output provides fluid status data to assist clinicians in managing patients with fluid-related conditions, potentially aiding in early warning of fluid status changes.
Clinical Evidence
Clinical performance data was submitted; however, specific study results, sample sizes, or statistical metrics were not detailed in the provided documentation. The device relies on substantial equivalence to predicate devices and compliance with electrical safety standards (UL 2601-1/CSA C22.2 No. 60601, EN 60601-1:2003, EN 60601-1-2).
Technological Characteristics
Thoracic base impedance monitor; battery-powered. Uses disposable silver/silver chloride electrodes. Complies with UL 2601-1, CSA C22.2 No. 60601, EN 60601-1:2003, and EN 60601-1-2 standards. Proprietary algorithm for Zo calculation.
Indications for Use
Indicated for patients with fluid management problems, those taking diuretic medication, living with heart failure, living with end-stage renal disease, recovering from coronary artery disease-related events, or suffering from recurrent dehydration. Contraindicated for patients with hydrogel allergies, skin sensitivities to hydrogel, or skin breakdown at chest electrode sites.
Regulatory Classification
Identification
An impedance plethysmograph is a device used to estimate peripheral blood flow by measuring electrical impedance changes in a region of the body such as the arms and legs.
Special Controls
*Classification.* Class II (special controls). The device, when it is a body composition analyzer which is not intended to diagnose or treat any medical condition, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 870.9.
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K042113
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SEP 1 4 2004
# ZOE™ Fluid Status Monitor
## 510(k) SPECIAL PREMARKET NOTIFICATION SUMMARY
- ZOE™ Fluid Status Monitor · Device Trade or Proprietary Name:
- · Common / Classification Name: Impedance Plethysmograph
- · Class: Class II Regulation Number: 870.2770 .
- Product Code: DSB
#### · Labeling:
Federal (United States) Law restricts this device to sale by or on the order of a physician or licensed healthcare professional.
#### · Predicate Device for Substantial Equivalence Comparison:
The ZOE™ Fluid Status Monitor, also referred to as ZOE or Zoe in the rest of this document, is claimed to be substantially equivalent to the following currently marketed Predicate Device and currently being marketed by NMT, LLC:
| Manufacturer | Device Name | 510-K Number | Decision Date |
|---------------------------------|-------------|--------------|-------------------|
| Renaissance<br>Technology, Inc. | IQ System™ | K922218 | December 08, 1992 |
| Renaissance<br>Technology, Inc. | IQ System™ | K981720 | February 08, 1998 |
### • Device Description:
The ZOE™ Fluid Status Monitor is a non-invasive, battery powered thoracic base impedance monitor designed as an 'early warning' monitor for determining changes in the fluid status of patients with fluid management problems.
The ZOE works by applying a minimal current to the patient. measuring electrical impedance changes throughout the thorax as aortic blood flow increases and decreases in response to each heartbeat. Base Impedance also known as Zo, decreases when fluid increases and rises when less fluid exists in the chest. This device incorporates a proprietary algorithm to calculate the Zo value.
The ZOE is designed for use with disposable, self-adhesive silver / silver chloride electrodes that are readily available / commercially approved within the United States for other approved cardiovascular monitoring systems.
- · Indications for Use Statement:
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K042113
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#### The ZOE™ Fluid Status Monitor is indicated for patients:
- With fluid management problems o
- Taking diuretic medication o
- Living with Heart Failure o
- Living with End-stage Renal Disease o
- Recovering from Coronary Artery Disease related event o
- Suffering from Recurrent Dehydration o
#### Contraindications for Use .
The ZOE™ Fluid Status Monitor is contraindicated for use with patients:
- With allergies to electrode hydrogel O
- Skin sensitivities to electrode hydrogel o
- Skin breakdown in areas on the chest where ZOE electrode placement is o required.
#### • Clinical Performance Data
Clinical performance data has been submitted.
#### · Rationale for Substantial Equivalence
- 1. The ZOE™ Fluid Status Monitor patient interface design is very similar to the predicate device [IQ System (Impedance Plethysmograph Monitor {DSB}) already approved by the FDA and currently being marketed by NMT, LLC]
- 2. The INTENDED USES and the OPERATING PRINCIPLES (i.e. Effectiveness) of the ZOE™ Fluid Status Monitor are the SAME as the Zo measurement function of the predicate device.
- 3. The OPERATIONAL FEATURES of the ZOE™ Fluid Status Monitor are the SAME or SIMILAR to those offered by the predicate device
- 4. The SAFETY FEATURES of the ZOE™ Fluid Status Monitor are the SAME or very SIMILAR to those offered by the predicate device.
Therefore, in summary, the ZOE™ Fluid Status Monitor is substantially equivalent to the Zo measurement feature in the identified predicate device that has previously been allowed for commercial distribution in the United States.
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## · Safety and Effectiveness
The ZOE™ Fluid Status Monitor complies with the electrical standards of the Underwriters Laboratories UL 2601-1 / CSA C22.2 No. 60601 and has passed an inspection to these standards by an independent testing house. The ZOE underwent independent scrutiny and testing to assess the overall electrical safety and EMI safety. The ZOE met all electrical and electromagnetic compatibility (EMI) safety requirements set forth in the European national Safety Requirements LVD Low voltage Directive testing to Safety of Medical Devices EN 60601-1:2003, EMC testing to Emissions / Immunity Requirements for EMC/EMI requirements for Medical Devices EN 60601-1-2 which reasonably assures the device is safe when used as directed for its prescribed intended use.
The ZOE does not raise any new issues of safety, effectiveness or performance of the device when compared to the existing predicate device.
#### · Conclusions
The data submitted in this 510(k) Premarket Notification, for the ZOE Fluid Status Monitor demonstrates that this product is substantially equivalent with respect to the indications for use, operating principles, operational features, and safety features to the identified legally marketed predicate device. With the information provided, the safety and effectiveness of the product can be reasonably assured, and we believe that this device clearly meets the requirement for a "Substantial Equivalence" decision in accordance with the 510(k) guidelines.
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Public Health Service
Image /page/3/Picture/2 description: The image is a black and white logo for the Department of Health & Human Services - USA. The logo is circular in shape, with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" arranged around the top half of the circle. Inside the circle is a stylized image of an eagle or bird-like figure, with three curved lines representing its wings or body.
Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850
SEP 1 4 2004
Noninvasive Medical Technologies, LLC c/o Mr. Alden Kay Consultant 4367 Tuolumne Place Carlsbad, CA 92008-7924
Re: K042113
Trade Name: ZOE™ Fluid Status Monitor Regulation Number: 21 CFR 870.2770 Regulation Name: Impedance Plethysmograph Regulatory Class: Class II (two) Product Code: DSB Dated: August 3, 2004 Received: August 5, 2004
Dear Mr. Kay:
We have reviewed your Section 510(k) premarket notification of intent to market the device we nave teviewed your becally be device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate for asc stated in the encreate to togally to togally the Medical Device Amendments, or to commerce prior to May 20, 1978, the excordance with the provisions of the Federal Food, Drug, devices that have been recuire approval of a premarket approval application (PMA). and Cosmetic Act (1101) market the device, subject to the general controls provisions of the Act. The 1 ou may, therefore, mailer are as act include requirements for annual registration, listing of general controls profices of of rectice, 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 If your device is classified (600 a00 ro) als. Existing major regulations affecting your device can may be subject to subli additions, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
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Page 2 - Mr. Alden Kay
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. This letter will allow you to begin marketing your device as described in your Section 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), please contact the Office of Compliance at (301) 594-4646. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). You may obtain other general information on your responsibilities under the Act 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/cdrh/dsma/dsmamain.html
Sincerely yours,
B/Bimmumer for
Prem D. Zuckerman, M.D.
Bram D. Zuckerman, M.D. Director Division of Cardiovascular Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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#### K042113 510(k) Number (if known):
Previously approved as: K981720
"ZOE™ Fluid Status Monitor" Impedance Plethysmograph Device Name:
#### Indications For Use:
As with the predicate devices indicated in this submission (cardiac monitors employing impedance plethysmography {DSB}):
The ZOE™ Fluid Status Monitor is intended for:
- With fluid management problems 0
- Taking diuretic medication ಂ
- Living with Heart Failure o
- Living with End-stage Renal Disease O
- Recovering from Coronary Artery Disease related event 0
- Suffering from Recurrent Dehydration O
The ZOE™ Fluid Status Monitor is contraindicated for use with patients:
- With allergies to electrode hydrogel 0
- Skin sensitivities to electrode hydrogel ্
- Skin breakdown in areas on the chest where ZOE clectrode placement is o required.
This device is intended for use by qualified health care practitioners, under the direction of a physician, for the non-invasive monitoring and management of patients with fluid management problems in a variety of medically accepted clinical applications.
Prescription Use (Per 21 CFR 801.109)
| | <b>OR Over-The-Counter Use</b> |
|--------------------------|------------------------------------------|
| Division Sign-Off) | |
| | Division of Cardiovascular, Respiratory, |
| and Neurological Devices | (optional form |
(4-methyl-1,3-dioxolan-2-one)
format: 1-2-96)
(PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NEEDED) Concurrence of CDRH, Office of Device Evaluation (ODE)
Bhiman
510(k) Number k042113
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.