K981976 · Microcurrent Research, Inc. · GZJ · Nov 25, 1998 · Neurology
Device Facts
Record ID
K981976
Device Name
ACUTRON MENTOR MODEL 961
Applicant
Microcurrent Research, Inc.
Product Code
GZJ · Neurology
Decision Date
Nov 25, 1998
Decision
SESE
Submission Type
Traditional
Regulation
21 CFR 882.5890
Device Class
Class 2
Attributes
Therapeutic
Indications for Use
The intended use of the Acutron Mentor is for relief of chronic intractable pain, some types of acute pain, and postoperative pain. It is applicable for a wide range of patients with pain, except those for which its use if contraindications for use are reproduced in the 510K submission K981976 in Section 11.0, preface pages 1 - 2. These include contraindications or cautions for patients with cardiac pacemakers, who are pregnant, are using electronic monitoring equipment, or with sensitive skin. It is also vital to obtain an accurate diagnosis of the cause of a patient's pain concurrent with TENS device use so that the overall condition can be addressed.
Device Story
Acutron Mentor is an electromedical TENS device delivering modulated electrical currents to soft tissues and peripheral nerves. Inputs include user-selected parameters (intensity, frequency, polarity, modulation, waveform) via LCD interface and command knob. Device transforms inputs into four independently controlled, isolated output channels (milliamp or microamp ranges). Outputs delivered via TENS pads or probe electrodes. Used in clinical settings by practitioners for pain management; provides simultaneous treatment for multiple patients with differing needs. Features include conductivity monitoring to ensure electrode-skin interface. Device benefits patients by providing non-invasive pain relief through electrical stimulation, utilizing Gate Control theory to modulate pain perception. System includes logic board with processors/memory, power supply, and output channel boards. Programmable memory stores up to 40 treatment sets.
Clinical Evidence
No clinical data provided. Substantial equivalence is based on technological characteristics and design comparisons to legally marketed predicate devices.
Technological Characteristics
Electromedical TENS device; ABS plastic chassis; four isolated output channels; LCD interface with command knob. Power: External AC/DC adapter with rechargeable backup battery. Waveforms: Pulsed milliamp, microcurrent, interferential (2500/4000 Hz), Russian current (2500 Hz carrier/50 Hz burst). Connectivity: Standalone. Microprocessor-controlled output voltages; A-D converters; isolation transformers. Conductivity monitoring per channel. Sterilization: Not applicable (external use).
Indications for Use
Indicated for symptomatic relief of chronic intractable pain, post-traumatic pain, and post-surgical pain. Contraindicated for patients with cardiac pacemakers, pregnant patients, patients using electronic monitoring equipment, or patients with sensitive skin.
Regulatory Classification
Identification
A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to electrodes on a patient's skin to treat pain.
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IC981976
Microcurrent Research, Inc.
3810 East Desert Cove Avenue Phoenix, AZ USA 85028 phone- (602) 494-5626 fax- (602) 953-0544
Image /page/0/Picture/4 description: The image shows the text "510K Summary" at the top. Below that, there is an oval shape that surrounds the text "K 981976". The text is in a bold, sans-serif font. The image appears to be a cropped portion of a larger document.
Microcurrent Research, Inc. (see letterhead) From: Submitter: Paul Davis, President Submitted August 28, 1998
- Commercial name: Acutron Mentor Device: Classification: TENS device (transcutaneous electric nerve stimulator)
## Legally marketed predicate devices:
- 1) Acutron Multiwave 911E: Manufactured by Microcurrent Research, Inc., Phoenix, AZ FDA 510K #K880042B
- 2) Theratouch 4.7: Manufactured by Rich-Mar, Inola, OK FDA 510K #K932868
- 3) Dynatron 550: Manufactured by Dynatronics, Salt Lake City, UT FDA 510K #K941577
# Description of device:
The Acutron Mentor is an electromedical device of advanced design that is capable of delivering precisely modulated currents of variable intensity, frequency, polarity, modulation and waveform configuration to the soft tissues and peripheral nerves of the body via transcutaneous stimulation. The Acutron uses a large, easy to read LCD screen for all treatment set-up and monitoring, which greatly speeds and simplifies usage. The Acutron has four independently controlled and electrically isolated output channels. The multiple outputs and variations of current configuration allow the user many invaluable options of affording comfortable and effective treatment to his or her patients. These are:
Conventional pulsed milliamp stimulator
Advanced microcurrent stimulator
Interferential stimulator with classic milliamp and microcurrent options
Russian current stimulator with fixed 2500 Hz carrier frequency with 50 Hz bursts
Until the release of the Acutron, a practitioner would usually have to purchase several different instruments to fulfill all of these treatment styles.
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Although electrical stimulation (ES) has now been in common use for pain management for over three decades, there are still differing opinions on exactly how it works, or exactly how to apply it. The Gate Control theory of pain postulated in 1965 by Melzack and Wall offered sufficient theoretical framework for the development of this technology. The Gate Theory states that externally applied electrical signals from a TENS unit can create enough of an input overload to the dorsal horn of the spinal cord via the C nerve fibers that there is less perception of pain signals through the slower A nerve fibers.
The Acutron Mentor offers two current ranges and several waveforms and current modulations. All parameters can be customized prior to or during treatment. The Acutron's two current ranges are milliamperage (0 - 60 mA) and microamperage (25 - 600 µA). Each output channel has its own treatment timer, offering many preset time options ranging from 4 seconds to 20 minutes, and continuous. Each channel also offers a conductivity test mode, with its own separate conductivity display on the LCD display. The purpose of this feature is to insure good conductive interface between the electrodes and the patient's skin at all times prior to and during treatment.
The device offers two methods of therapeutic current application- probe and pad electrodes. Pad channels utilize conventional TENS pads as interface with the patient's skin. Probe electrodes have wells in the probe tips to accept cut-off tips of cotton swabs, which are wetted for creating a conductive interface. The Acutron Mentors four channels are designated by letters A, B, C, and D. Channels A, B and C each stimulate a set of two TENS pads. Channel D is a dual channel which can be used to power either a fourth set of TENS pads or a set of two probe electrodes (not both). Due to the advanced design of the Acutron Mentor, the channels can be programmed together or separately. If programmed separately, each channel can output a completely different set of parameters such as frequency, waveform, modulation, polarity and treatment time. This feature can allow for the simultaneous treatment of several patients with differing needs.
The Acutron Mentor design is composed of four separate circuit boards. There is one logic board, which contains the LCD display and includes the main processors and memory chips. There is one power supply board, which receives 18 volts DC current from the external AC/DC adapter and converts this to all the necessary voltages needed for logic. therapeutic currents and communications. There are also two output channel boards, each of which contains the circuitry for two of the output channels. This design allows for easy servicing and upgrades, and maintains strict electronic isolation betwen the four channels. and between the power supplies and output circuitry. The Acutrons chassis is made of rugged custom molded ABS plastic, and all external controls and jacks are electronically isolated from AC mains and current outputs.
## Intended use of device
The intended use of the Acutron Mentor is for relief of chronic intractable pain, some types of acute pain, and postoperative pain. It is applicable for a wide range of patients with pain, except those for which its use if contraindications for use are reproduced in the 510K submission K981976 in Section 11.0, preface pages 1 - 2. These include contraindications or cautions for patients with cardiac pacemakers, who are pregnant, are using electronic monitoring equipment, or with sensitive skin. It is also vital to obtain an accurate diagnosis of the cause of a patient's pain concurrent with TENS device use so that the overall condition can be addressed.
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# Comparison of technological characteristics
There are many similarities, and some important differences, between the old and new model Acutron devices. These are listed below. The old model will be referred to as "Old" and the new model "New":
#### A. Similarities
1) Combination of digital and analog electronic design, utilizing A-D converters, isolation transformers, and microprocessor controlled output voltages
2) Use of double sided PC board(s)
3) Four isolated output channels
4) Ability to switch between milliamp and microamp outputs on channels.
5) Conductivity monitoring on each output channel
6) Ability by user to modify waveform, polarity, intensity, modulation, and treatment time
7) Rechargeable battery for portabiity of unit
8) Many circuits and components in the output areas of the circuit boards are the same or very similar between the two devices
9) Two types of electrodes - TENS pads and probe electrodes with cotton swab or metal tip contacts
# B. Differences
1) Chassis: Old- Metal chassis. New- molded ABS plastic chassis
2) User interface: Old- manual knobs and switches for all adjustments. New- all set-up and adjustments done through pressing buttons around LCD display and depressing and turning Command Knob
3) Power supply: Old- External charger charged two rechargeable batteries, unit could only run off batteries. New- External AC/DC adapter directly powers the Power Supply PCB, secondarily trickle charging rechargeable backup battery. Please see additional information in this package, page 3, for safety information about new unit. In summary, through double fusing, transformer isolation, double sense resistors, and current limiting surge protection, the new unit is at at least as safe as the old unit, probably more so.
4) Qutput currents: New unit offers several additional waveforms and modulations requested by our customers. The most significant new offering is sine wave milliamperage in the 2500 and 4000 Hz ranges, respectively, for Russian stimulation and interferential currents.
5) Programmability: Old- User can preprogram one set of "basic" parameters. New- user can preprogram up to 40 sets of treatment parameters, storing them in memory
6) Qutput channels: Old- three channels for pad output, one for probe output only. New-Probe output offered on channel D, however, all four channels can be used for pad output if desired
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Image /page/3/Picture/2 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo is a circular seal with the words "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" around the perimeter. Inside the circle is a stylized image of an eagle with three lines representing its wings and body. The eagle is facing to the right.
Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850
# Nov 2 5 1998
Mr. Paul Davis President Microcurrent Research, Inc. 3810 East Desert Cove Avenue Phoenix, Arizona 85028
Re: K981976 Trade Name: Mentor 961 Acutron TENS Regulatory Class: II Product Code: GZJ Dated: August 26, 1998 September 2, 1998 Received:
Dear Mr. Davis:
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 The general controls provisions of the Act 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. ಗ್ನಿ substantially equivalent determination assumes compliance with the current Good Manufacturing Practice requirement, 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 In addition, FDA may publish further announcements action. concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obliqation 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 requlations.
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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 requlation (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" (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,
Celia M. Witten. Ph.D.
ia M. Witten, Ph.D., M.D. - Cel Director Division of General and Restorative Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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510(k) NUMBER (IF KNOWN): K981976
Acutron Mentor DEVICE NAME:
INDICATIONS FOR USE:
:/
Symptomatic relief of chronic intractable pain, post-traumatic and post-surgical pain.
(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
(Optional Format 1-2-96)
bosely
(Division Sign-Off)
(Division \$ign-Off)
Division of General Restorative Devices K981976
510(k) Number
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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.