The intended use of the Quinton Electrophysiology Corporation's EPXpress System (Timberwolf Revision) is the acquisition, amplification, display, recording, and transmission of electrical signals of biological origin obtained during electrophysiology studies and related procedures. Such signals include ECG, intracardiac ECG, and blood pressure. Physiological parameters as diastolic, systolic, and mean blood pressure, heart rate, and cycle length may be derived from these signals and displayed numerically, recorded, and/or transmitted. Additionally, the EPXpress System (Timberwolf Revision) may acquire, transpose, amplify, display, record and transmit measurement data received from other medical devices typically used during these procedures, such as oximeters, RF generators, or electronic thermometers.
Device Story
EPXpress System (Timberwolf Revision) is an integrated catheter switching, amplification, and display system for electrophysiology labs. Inputs include electrical signals from intracardiac catheters, ECG, and blood pressure data; also receives measurement data from auxiliary devices (oximeters, RF generators, thermometers). System components (EPAmp, Real-Time Controller, monitor) typically mounted on a mobile cart. Device amplifies/conditions signals for real-time display on monitor or output to chart recorder. Timberwolf Revision adds numerical display of systolic, diastolic, and mean blood pressure, heart rate, and cycle length. Operated by clinical staff in electrophysiology labs. Output provides clinicians with real-time physiological monitoring to assist in procedural decision-making and patient assessment during electrophysiology studies.
Clinical Evidence
Bench testing only. Prospective paired comparison study using controlled, repeatable simulated inputs (dynamic IVBP waveforms: left ventricular, aortic, left arterial, pulmonary capillary wedge, pulmonary arterial). Evaluated accuracy of systolic, diastolic, and mean blood pressure measurements across 0-300 mmHg range. Results demonstrated equivalence to predicate (Q-Cath) at 95% confidence level (p < 0.05) with mean differences < +/- 2 mmHg.
Technological Characteristics
Integrated catheter switching, amplification, and display system. Components: EPAmp, Real-Time Controller, monitor. Mobile cart form factor. Signal processing: amplification and conditioning of biopotential signals. Connectivity: receives data from external medical devices (oximeters, RF generators, thermometers). Output: real-time monitor display and chart recorder interface. Software: numerical derivation of blood pressure and heart rate parameters from analog waveforms.
Indications for Use
Indicated for patients undergoing electrophysiology studies and related procedures requiring acquisition, amplification, display, recording, and transmission of biological signals including ECG, intracardiac ECG, and blood pressure.
Regulatory Classification
Identification
A biopotential amplifier and signal conditioner is a device used to amplify or condition an electrical signal of biologic origin.
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# K971570
DEC 29 1997
## 510(k) SUMMARY
| Submitter's Name: | Quinton Electrophysiology Corporation |
|---------------------------|---------------------------------------------------------------------------|
| Submitter's Address: | 200 West Beaver Creek Road<br>Richmond Hill, Ontario<br>Canada<br>L4B 1B4 |
| Submitter's Phone Number: | (Canada) 905-709-1726 |
| Submitter's Fax Number: | (Canada) 905-709-1736 |
| Contact Person: | Dr. Harold Wodlinger |
| Date Summary Prepared: | July 16, 1997 |
| | |
A. Device Name and Classification
1) Device Trade Name: EPXpress System (Timberwolf Revision)
2) Device Common Name: Physiological Monitoring System
- 3) Device Classification Names
- 870.2340 Electrocardiograph
- 870.2050 Biopotential Amplifier and Signal Conditioner
870.1425 Programmable Diagnostic Computer
- 870.1110 Blood Pressure Computer
- 870.2450 Medical Cathode Ray Tube Display
- 870.2810 Paper Chart Recorder
- B. Predicate Device
The legally marketed device to which we claim equivalence is the PE Electrophysiology Lab System and CardioLab Amplifier Module both manufactured by Prucka Engineering, Inc. . The 510(k) numbers for these devices are K902716 and K910307, respectively. Additionally, we claim equivalence to the Quinton Q-Cath System manufactured by Quinton Instrument Company. The 510(k) number for this device is K862740.
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#### C. Device Description
The EPXpress System (Timberwolf Revision) is an integrated catheter switching amplification and display system that can be installed at the patient table in the electrophysiology lab or moved to other locations where particular procedures may require its use. The system is made up of the EPAmp, Real-Time Controller, and monitor that are usually mounted on a cart. The EPAmp unit amplifies and conditions electrical signals from intracardiac catheters and displays these signals on a real-time monitor and/or prints these results to a chart recorder. The Timberwolf Revision added the capability of numerically displaying diastolic, systolic and mean blood pressures, as well as heart rate, cycle length, and certain measurement data received from other instruments.
#### D. Intended Use of Device
The intended use of the Quinton Electrophysiology Corporation's EPXpress System (Timberwolf Revision) is the acquisition, amplification, display, recording, and transmission of electrical signals of biological origin obtained during physiological studies and related procedures. Such signals include ECG, intracardiac ECG, and blood pressure. Physiological parameters as diastolic, systolic, and mean blood pressure, heart rate, and cycle length may be derived from these signals and displayed numerically, recorded, and/or transmitted. Additionally, the EPXpress System may acquire, transpose, amplify, display, record and transmit measurement data received from other medical devices typically used during these procedures, such as oximeters, RF generators, or electrical thermometers.
E. Summary of Technological Characteristics Compared with the Predicate Device
The EPXpress System (Timberwolf Revision) and the predicate devices described above have amplifiers which condition incoming physiological signals. The physiological signals acquired by the EPXpress and the predicate devices include ECG. intracardiac ECG. and blood pressure. Both the EPXpress and the predicate devices may display this physiological data on a monitor or the data may be printed out on chart recorder. All systems use a mobile cart for transport and have similar power and environmental requirements. The predicate devices have hardware and software which allow for the analysis of the physiological signals. The EPXpress System does not have this capability other than the ability to transform certain waveform data into numerial displays (Timberwolf Revision). (The analysis function is supplied by the EPLab System working in conjunction with the EPXpress System)
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#### F. Performance Testing and Conclusions
#### 1) Performance Testing
Performance testing was an equivalence study comparing blood pressure measurements taken and numerically displayed by the EPXpress System (Timberwolf Revision) with blood pressure measurements obtained and displayed in a similar fashion by a predicate device, the Quinton Q-Cath Monitoring and Analysis System. The study was a prospective paired comparison of measurements done using a controlled, repeatable simulated input. Measurement values were selected from the range of available, pre-set values provided by a simulator. The measurement values covered the specified range for the EPXpress System ( i.e. 0-300 mmHg systolic and mean, -30 to 300 mmHg diastolic) using dynamic IVBP waveforms - left ventricular, aortic, left arterial, pulmonary capillary wedge, and pulmonary arterial waveforms. This range of waveforms provided low, medium, and high values for systolic, diastolic, and mean pressures.
It was formulated that the EPXpress System (Timberwolf Revision) would be considered subtantially equivalent to its predicate device with respect to IVBP measurements if it could be shown at the 0.05 confidence level that the mean difference between each pair of diastolic, systolic, and mean measurements is less than +/- 2 mmHq.
## 2) Conclusions
The study results met the above criteria for substantial equivalence. Using a +/- 5% equivalence region, the study results showed that the Timberwolf can be regarded as equivalent to Q-Cath at the 95% confidence level (i.e., 0.05 significance level) for phasic IVBP systolic, diastolic, and mean pressure measurements in the range of 0-300 mmHq.
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Image /page/3/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a circular seal with the words "DEPARTMENT OF HEALTH & HUMAN SERVICES • USA" arranged around the perimeter. Inside the circle is an abstract image of an eagle with its wings spread.
Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850
Quinton Electrophysioloqy Corporation c/o Mr. Matt Hedlund Regulatory Coordinator Quinton Instrument Company 3303 Monte Villa Parkway Bothell, Washington 98021-8906
DEC 2 9 1997
Re : K971570 The EPXpress System (Timberwolf Revision) Regulatory Class: II (two) Product Code: 74 DRR Dated: September 26, 1997 Received: October 2, 1997
Dear Mr. Hedlund:
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, 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 A substantially equivalent determination assumes compliance with 895. 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 action. In addition, FDA may publish further announcements 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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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) 594-4648. 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/dsmamain.html" .
Sincerely yours,
Thomas J. Callehan
Thomas J. Callahan, Ph.D. Director Division of Cardiovascular, Respiratory, and Neurological Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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k971570 510(k) Number (if known): ____________________________________________________________________________________________________________________________________________________
Device Name: _________________________________________________________________________________________________________________________________________________________________
Indications for Use:
The intended use of the Quinton Electrophysiology Corporation's EPXpress System (Timberwolf Revision) is the acquisition, amplification, display, recording, and transmission of electrical signals of biological origin obtained during electrophysiology studies and related procedures. Such signals include ECG, intracardiac ECG, and blood pressure. Physiological parameters as diastolic, systolic, and mean blood pressure, heart rate, and cycle length may be derived from these signals and displayed numerically, recorded, and/or transmitted.
Additionally, the EPXpress System (Timberwolf Revision) may acquire, transpose, amplify, display, record and transmit measurement data received from other medical devices typically used during these procedures, such as oximeters, RF generators, or electronic thermometers.
(PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NEEDED)
| Concurrence of CDRH, Office of Device Evaluation (ODE) | |
|--------------------------------------------------------|---------|
| (Division Sign-Off) | |
| Division of Cardiovascular, Respiratory, | |
| and Neurological Devices | |
| 510(k) Number | K971570 |
| Prescription Use | OR | Over-The-Counter Use |
|------------------|----|----------------------|
|------------------|----|----------------------|
(Optional Format 1-2-96)
## 000008
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Learn the FDA Browser
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.