Zenith is an electroneurodiagnostic device that accepts, measures, and stores electrical activity of the brain via scalp and intracranial electroencephalography (EEG) signals, and, utilizing an integrated switch matrix, relays stimulation signals to the patient. It can obtain, display and store electrophysiological data from the central nervous system, generated either spontaneously or elicited by well-defined stimuli. The data is used to perform neurodiagnostic evaluations, including EEG and direct cortical stimulation. Zenith Cadwell acquisition software. Zenith is used by or under the direction of a licensed physician, surgeon, or neurologist in a professional healthcare facility environment for pre-operative, intraoperative testing on patients of all ages.
Device Story
High channel-count EEG system; acquires, stores, and reviews neurophysiological data; performs cortical stimulation via optional stimulator and integrated switch matrix. Inputs: scalp/intracranial EEG signals; photic stimulation; pulse oximetry. Operation: computer-based equipment with dedicated hardware (amplifiers, IOMAX base/cortical modules) and custom acquisition software. Used in professional healthcare facilities (pre-operative, intraoperative, post-operative) by physicians, surgeons, or neurologists. Output: displayed/stored electrophysiological data and reports. Clinicians use output for neurodiagnostic evaluations and direct cortical stimulation guidance. Benefits: enables comprehensive monitoring of central nervous system activity.
Clinical Evidence
Bench testing only. No clinical data provided. Performance verified against IEC 60601-2-26 (electroencephalographs), IEC 60601-2-40 (electromyographs/evoked response), and usability standards (IEC 60601-1-6, IEC 62366-1). Electrical safety and EMC testing performed per ANSI/AAMI ES60601-1 and IEC 60601-1-2.
Indicated for patients of all ages requiring neurodiagnostic evaluations, including EEG and direct cortical stimulation, in professional healthcare facilities under the direction of a licensed physician, surgeon, or neurologist.
Regulatory Classification
Identification
An electroencephalograph is a device used to measure and record the electrical activity of the patient's brain obtained by placing two or more electrodes on the head.
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Image /page/0/Picture/0 description: The image contains the logo of the U.S. Food and Drug Administration (FDA). On the left is the Department of Health & Human Services logo. To the right of that is the FDA logo, which consists of a blue square with the letters "FDA" in white, followed by the words "U.S. FOOD & DRUG ADMINISTRATION" in blue.
September 1, 2018
Cadwell Industries, Inc. John Cadwell Jr Senior Vice President 909 North Kellogg Street Kennewick, Washington 99336
Re: K181466
Trade/Device Name: Cadwell Zenith System Regulation Number: 21 CFR 882.1400 Regulation Name: Electroencephalograph Regulatory Class: Class II Product Code: GWQ, GYC, GWF, ETN Dated: June 1, 2018 Received: June 4, 2018
Dear John Cadwell Jr:
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
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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); 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/CombinationProducts/GuidanceRegulatoryInformation/ucm597488.htm); 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 http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm.
For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/) and CDRH Learn (http://www.fda.gov/Training/CDRHLearn). 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 (http://www.fda.gov/DICE) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).
Sincerely.
# Jay R. Gupta -S
For Carlos L. Peña, PhD, MS Director Division of Neurological and Physical Medicine Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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### Indications for Use
510(k) Number (if known) K181466
Device Name Cadwell Zenith System
#### Indications for Use (Describe)
Zenith is an electroneurodiagnostic device that accepts, measures, and stores electrical activity of the brain via scalp and intracranial electroencephalography (EEG) signals, and, utilizing an integrated switch matrix, relays stimulation signals to the patient. It can obtain, display and store electrophysiological data from the central nervous system, generated either spontaneously or elicited by well-defined stimuli. The data is used to perform neurodiagnostic evaluations, including EEG and direct cortical stimulation. Zenith Cadwell acquisition software.
Zenith is used by or under the direction of a licensed physician, surgeon, or neurologist in a professional healthcare facility environment for pre-operative, intraoperative testing on patients of all ages.
X Prescription Use (Part 21 CFR 801 Subpart D)
Over-The-Counter Use (21 CFR 801 Subpart C)
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| Submission Date: | 01 June 2018 | | |
|-----------------------------------------------|----------------------------------------------------------------------------------------------|----------------------------|--------------------------------------------------------------------------------------------|
| Submitter: | Cadwell Industries, Inc.<br>909 North Kellogg Street<br>Kennewick, WA 99336 | | |
| Submitter and<br>Application<br>Correspondent | Mr. John Cadwell Jr.<br>Phone: +1 (800) 245-3001, Extension 222<br>Email: johnjr@cadwell.com | | |
| Manufacturing Site: | Cadwell Industries, Inc.<br>909 North Kellogg Street<br>Kennewick, WA 99336 | | |
| Trade Name: | Cadwell Zenith System | | |
| Common and<br>Classification<br>Name: | Electroencephalograph | | |
| Primary<br>Classification<br>Regulation: | 21 CFR §882.1400 | | |
| Primary Product<br>Code: | GWQ | | |
| Secondary Product<br>Codes: | GYC, GWF, ETN | | |
| Substantially<br>Equivalent Devices: | New Cadwell Model | Predicate<br>510(k) Number | Predicate<br>Manufacturer / Model |
| | Cadwell Zenith System | K143440,<br>K180181 | Natus Medical<br>Incorporated DBA Excel-<br>Tech Ltd. (XLTEK) /<br>Natus Quantum (primary) |
| | | K162199 | Cadwell Industries Inc. /<br>Cascade IOMAX<br>Interoperative Monitor |
(secondary)
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Device Description: The Cadwell Zenith System is a high channel-count Electroencephalogram (EEG) system capable of cortical stimulation via the optional stimulator and built in switch matrix. The system is capable of acquiring, storing, and reviewing neurophysiological data and report generation. The Cadwell Zenith System can be configured in a portable or fixed room configuration. Carts are available for purchase with the system. The Cadwell Zenith System consists of one (1) or more Zenith amplifiers, an IOMAX Base Module, and an optional IOMAX Cortical Module. Additionally, a Patient Event Button, USB Photic Stimulator, and USB Footswitch can be purchased separately Indications for Use: Zenith is an electroneurodiagnostic device that accepts, measures, displays, records, and stores electrical activity of the brain via scalp and intracranial electroencephalography (EEG) signals, and, utilizing an integrated switch matrix, relays stimulation signals to the patient. It can obtain, display and store electrophysiological data from the central nervous system, generated either spontaneously or elicited by welldefined stimuli. The data is used to perform neurodiagnostic evaluations, including EEG and direct cortical stimulation. Zenith is used with Cadwell acquisition software. Zenith is used by or under the direction of a licensed physician, surgeon, or neurologist in a professional healthcare facility environment for preoperative, intraoperative and post-operative testing on patients of all ages. Technology The Cadwell Zenith System employs the same technological Comparison: characteristics as the predicate device. Predicate Device Characteristic Proposed Device
| Population | Patients of all ages. | Patients of all ages, but is not<br>designed for fetal use |
|-------------------------|--------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------|
| System<br>Configuration | Computer based equipment with<br>dedicated hardware<br>peripherals/components, and custom<br>acquisition software. | Computer based equipment with<br>dedicated hardware<br>peripherals/components, and custom<br>acquisition software. |
| Modalities | Electroencephalogram (EEG)<br>External cortical stimulation<br>Photic stimulation<br>Video | Electroencephalogram (EEG)<br>External cortical stimulation<br>Photic stimulation<br>-<br>Pulse oximetry |
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| Characteristic | Proposed Device | Predicate Device |
|------------------------------------------------------------|-----------------------------------------------------------------|-----------------------------------------------------------------|
| Amplifier<br>Channels | 144 channels per amplifier, cascade-<br>able up to 576 channels | 128 channels per amplifier, cascade-<br>able up to 256 channels |
| | • 144 referential channels per<br>amplifier | • 128 referential channels per<br>amplifier |
| | • 8 differential channels per<br>amplifier | • Up to 8 configurable differential<br>channels per amplifier |
| | • 0 DC channels per amplifier | • 16 DC channels per amplifier |
| Number of<br>Amplifiers that<br>can Connect to<br>Recorder | Four (4) | Two (2) |
| Input Impedance | 1 GΩ | >1000 ΜΩ |
| Input Noise | <1.5 µV peak-to-peak at 01.-100 Hz | <2.0 µV peak-to-peak at 01.-100 Hz |
| Input Signal<br>Range | > 25 mV peak-to-peak | 20 mV peak-to-peak |
| Maximum DC<br>Input Voltage<br>Offset | > ±500 mV | ±300 mV |
| Common Mode<br>Rejection Ratio | >110 dB at 60Hz | >106 dB at 60 Hz |
| Sampling<br>Frequency | 1 MHz | 256, 512, 1024, 2048, 4096, 8192,<br>16384 Hz |
| Storage Rate | Up to 8 kHz | |
| Sampling A/D<br>Resolution | 24 bits | 24 bits |
| Cortical stimulator<br>output | Output mode: Low<br>Output type: Constant current | Output mode: Low<br>Output type: Constant current |
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### Summary of Performance Testing:
| Software | The Cadwell acquisition software is MODERATE level of concern software. Software was designed and developed according to a robust software development process, and was rigorously verified and validated. Software information is provided in accordance with internal requirements and the following guidance documents:<br>FDA guidance: The content of premarket submissions for software contained in medical devices, 11 May 05. FDA guidance: Off-the-shelf software use in medical devices, 09 Sep 99. FDA guidance: General principles of software validation; Final guidance for industry and FDA staff, 11 Jan 02. FDA guidance: Content of premarket submissions for management of cybersecurity in medical devices, 02 Oct 14. IEC 62304: 2006, Am1: 2015, Medical device software - Software life cycle processes Test results indicate that the Cadwell acquisition software complies with its predetermined specifications and the applicable guidance documents. |
|----------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Electrical Safety | The Cadwell Zenith System was tested for performance in accordance with the following standard:<br>ANSI/AAMI ES60601-1: 2005/(R)2012, Am1: 2012, C1:2009/(R)2012 A2:2010/(R)2012, Medical electrical equipment – Part 1: General requirements for basic safety and essential performance. Test results indicate that the Cadwell Zenith System complies with the applicable standards. |
| Electromagnetic<br>Compatibility | The Cadwell Zenith System was tested for performance in accordance with the following standard:<br>IEC 60601-1-2: 2014, Medical electrical equipment – Part 1-2: General requirements for basic safety and essential performance – Collateral standard: Electromagnetic disturbances – Requirements and tests. Test results indicate that the Cadwell Zenith System complies with the |
applicable standards.
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Performance The Cadwell Zenith System was tested for performance in accordance Testing – Bench with internal requirements and the following standards: IEC 60601-2-26: 2012, Medical electrical equipment – Part 2-26: ● Particular requirements for the basic safety and essential performance of electroencephalographs ● IEC 60601-2-40: 2016, Medical electrical equipment – Part 2-40: Particular requirements for the safety of electromyographs and evoked response equipment ● IEC 60601-1-6: 2013, Medical electrical equipment - Part 1-6: General requirements for basic safety and essential performance -Collateral standard: Usability • IEC 62366-1: 2015, Medical devices – Application of usability engineering to medical devices. Test results indicate that the Cadwell Zenith System complies with its predetermined specifications and the applicable standards. Conclusion Verification and validation activities were conducted to establish the performance and safety characteristics of the Cadwell Zenith System. The results of these activities demonstrate that the Cadwell Zenith System is as safe, as effective, and performs as well as or better than the predicate devices. Therefore, the Cadwell Zenith System is considered substantially
equivalent to the predicate devices.
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1. Search: exact and fuzzy
Type a phrase like "coronary artery calcification" into the search box. You get two kinds of results. Exact results match the literal phrase — prefix searches work ("coronary artery calcificati") but suffix searches do not. Fuzzy results match on the meaning and intent of your phrase rather than the exact words, and are sorted by relevance score. Hover over the Exact or Fuzzy badge on any row to see exactly why it matched.
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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).
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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.
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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.
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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.
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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.