K990787 · Ito Co., Ltd. · IPF · Oct 20, 1999 · Physical Medicine
Device Facts
Record ID
K990787
Device Name
TRIO 300
Applicant
Ito Co., Ltd.
Product Code
IPF · Physical Medicine
Decision Date
Oct 20, 1999
Decision
SESE
Submission Type
Traditional
Regulation
21 CFR 890.5850
Device Class
Class 2
Attributes
Therapeutic
Indications for Use
The TENS and Microcurrent modes of the Trio 300 are indicated for the symptomatic relief of chronic intractable pain. They are also indicated for the treatment of post-traumatic and post-surgical pain. The electrical muscle stimulation (EMS) mode is indicated for relaxation of muscle spasm, prevention or retardation of disuse muscle atrophy, muscle re-education, increase local blood circulation, maintain or increase range of motion, immediate post-surgical stimulation of calf muscles to prevent venous thrombosis.
Device Story
Trio 300 is a portable, battery-powered, dual-channel electrical stimulator; provides four stimulation modes: TENS, EMS, microcurrent, and programmable. Device uses surface electrodes to deliver electrical pulses to patient; controlled via LED/LCD screen interface with SELECT, SET, and arrow keys for parameter adjustment. Operates on battery or AC adapter. Used in clinical or home settings under physician direction. Healthcare providers use device to manage pain and support physical therapy goals; output affects clinical decision-making by providing non-pharmacological pain relief and muscle rehabilitation. Benefits include reduced pain, improved muscle function, and prevention of venous thrombosis.
Clinical Evidence
No clinical data. Bench testing only. Device compliance verified against electrical safety standards EN-60601 and electromagnetic compatibility standard EN 60601-1-2. Design qualification testing confirmed device met design specifications.
Technological Characteristics
Portable, battery-powered electronic pulse generator; microprocessor-based with digital and analog circuits. Features dual-channel output and LCD user interface. Supplied with surface electrodes (2"x2" and 2"x3.5"). Energy source: battery or AC adapter. Connectivity: none. Sterilization: not specified.
Indications for Use
Indicated for patients requiring symptomatic relief of chronic intractable, post-traumatic, or post-surgical pain (TENS/Microcurrent modes) or muscle spasm relaxation, prevention/retardation of disuse atrophy, muscle re-education, increased local blood circulation, maintenance/increase of range of motion, and post-surgical calf muscle stimulation to prevent venous thrombosis (EMS mode).
Regulatory Classification
Identification
A powered muscle stimulator is an electrically powered device intended for medical purposes that repeatedly contracts muscles by passing electrical currents through electrodes contacting the affected body area.
Bio-Medical Research Model NT2000 Stimulator (K972244)
Submission Summary (Full Text)
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/K550787
## 510(k) Summary
# Trio 300 Multi-Mode Electical Stimulator
Common/Classification Name: 21 CFR 882.5890, 21 CFR 890.5850
lto Co., Ltd. 3-3-3 Toyotama-Minami Nerima-ku, Tokyo 176-8605 JAPAN
Contact: H. Okada , Prepared: March 8, 1999
### LEGALLY MARKETED PREDICATE DEVICES A.
The Trio 300 Multi-Mode Electrical Stimulator is a device that combines four types of electrical stimulation in one device. It has a TENS mode, an electrical muscle stimulation mode, a microcurrent mode, and a general programmable mode. Since it appears that this particular combination of modes has not been present to date in any single device, it is necessary to claim substantial equivalence to more one predicate device. The TENS, microcurrent, and than programmable modes of the Trio 300 Multi-Mode Electrical Stimulator are substantially equivalent to the corresponding modes of the Acutron Mentor Model 961 (K981976). The electrical muscle stimulation (EMS), TENS, and programmable modes of the Trio 300 Multi-Mode Electrical Stimulator are substantially equivalent to the Bio-Medical Research Model NT2000 Stimulator (K972244).
#### B. DEVICE DESCRIPTION
The Trio 300 Multi-Mode Electrical Stimulator is a small, portable, battery-powered electrical stimulator device that has four stimulation modes, (1) TENS, (2) EMS, (3) microcurrent, and (4) programmable. The device has an LED screen that serves as the interface with the user to specify options, provide messages, and display parameters. The device is supplied with an AC adaptor for line current operation.
The Trio 300 consists of the pulse generator, A/C power adapter, and the surface electrodes.
The Trio 300 is a dual-channel electrical stimulator with four output modes. The device is equipped with a liquid crystal display (LCD) for communication with the user. The SELECT key allows the user to scroll through the options (e.g., mode) available at a particular point and the
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SET key allows the selection of the displayed option. The UP-ARROW and DOWN-ARROW keys allow the user to increase or decrease certain selected parameters.
#### C. INTENDED USE
The TENS mode of the Trio 300 is indicated for the symptomatic relief of chronic intractable pain. It is also indicated for the treatment of post-traumatic and post-surgical pain. The electrical muscle stimulation (EMS) mode is indicated for relaxation of muscle spasm, prevention or retardation of disuse muscle atrophy, muscle reeducation, increase local blood circulation, maintain or increase range of motion, immediate post-surgical stimulation of calf muscles to prevent venous thrombosis.
#### D. SUBSTANTIAL EQUIVALENCE SUMMARY
The Trio 300 Multi-Mode Electrical Stimulator is a medical device, and it has the same indications for use and target population as the legally marketed predicate devices. The Trio 300 Multi-Mode Electrical Stimulator has the same technological characteristics as the predicate devices. This premarket notification will describe the characteristics of the Trio 300 Multi-Mode Electrical Stimulator in sufficient detail to assure substantial equivalence except for a few of the characteristics where performance testing was carried out (e.g., electrical safety).
#### E. TECHNOLOGICAL CHARACTERISTICS
The Trio 300 and one of the predicate devices all portable, batterypowered, electronic pulse generator devices with surface electrodes. The Trio 300 and both predicate devices are microprocessor-based and employ digital and analog circuits to produce the specified waveforms and levels. All employ an LCD screen as the user interface.
The electrodes that will be supplied with the Trio 300 Multi-Mode Electrical Stimulator are manufactured in the U.S. by Axelgaard Manufacturing Company and are currently marketed products (K970426). Two sizes are available, 2″ by 2″ and 2″ by 3.5″.
#### F. TESTING
Testing was carried out to assure compliance with recognized electrical safety standards. Ito has certified compliance with the EN-60601 standard for electrical safety. Testing to UL 2601 is in progress.
TUV has issued an Attestation of Conformity for the Trio 300 in regard
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to the EN 60601-1-2 standard for electromagnetic compatibility.
The design qualification testing demonstrated that the Trio 300 met its design specifications.
#### G. CONCLUSION
This pre-market submission has demonstrated Substantial Equivalence as defined and understood in the Federal Food Drug and Cosmetic Act and various guidance documents issued by the Center for Devices and Radiological Health.
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Image /page/3/Picture/1 description: The image is a black and white circular seal for the Department of Health & Human Services - USA. The seal features the department's name in a circular arrangement around the perimeter. In the center of the seal is a stylized image of an eagle or bird-like figure with three distinct, curved lines representing its body and wings. The overall design is simple and conveys a sense of official government authority.
Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850
OCT 20 1999
T. Whit Athey, Ph.D. Senior Consultant Representing ITO Co., Ltd. C.L. McIntosh & Associates, Inc. 12300 Twinbrook Parkway, Suite 625 Rockville, Maryland 20852
K990787 Re: Trade Name: Trio 300 Multi-Mode Electrical Stimulator Regulatory Class: II Product Codes: IPF, GZJ Dated: July 21, 1999 Received: July 21, 1999
Dear Dr. Athey:
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 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). 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 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 (QS) for Medical Devices: General regulation (21 CFR Part 820) and that,
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Page 2 - T. Whit Athey, Ph.D.
through periodic QS inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in requlatory 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.
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) 594-4659. 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" (21CFR 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/dsma/dsmamain.html".
Sincerely yours,
Calvin M. Hite, Ph.D.
Witten, M. Ph.D., M.D. Director Division of General and Restorative Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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### STATEMENT OF INDICATIONS FOR USE
510(k) Number (if known): ____________________________________________________________________________________________________________________________________________________
Device Name:
Indications For Use:
The TENS and Microcurrent modes of the Trio 300 are indicated for the symptomatic relief of chronic intractable pain. They are also indicated for the treatment of post-traumatic and post-surgical pain. The electrical muscle stimulation (EMS) mode is indicated for relaxation of muscle spasm, prevention or retardation of disuse muscle atrophy, muscle re-education, increase local blood circulation, maintain or increase range of motion, immediate post-surgical stimulation of calf muscles to prevent venous thrombosis.
(PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NEEDED)
Concurrence of CDRH, Office of Device Evaluation (ODE)
Prescription Use (Per 21 CFR 801.109)
OR
Over-The-Counter Use
Dcoello
ivision oNGeneral Restorative Devic 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.