K031900 · Ness-Neuromuscular Electrical Stimulation Systems · GZI · Aug 8, 2003 · Neurology
Device Facts
Record ID
K031900
Device Name
HANDMASTER
Applicant
Ness-Neuromuscular Electrical Stimulation Systems
Product Code
GZI · Neurology
Decision Date
Aug 8, 2003
Decision
SESE
Submission Type
Special
Regulation
21 CFR 882.5810
Device Class
Class 2
Attributes
Therapeutic
Indications for Use
The Handmaster is intended to be used for the following indications: Maintenance or increase of range of motion, reduction of muscle spasm, prevention or retardation of disuse atrophy, muscle reeducation, and increasing local blood circulation. In patients suffering from upper limb paralysis due to C5 spinal cord injury or hemiplegia due to stroke, it is also intended to provide hand active range of motion and hand function.
Device Story
Handmaster is a portable, one-channel neuromuscular electrical stimulator for personal use. System includes a control unit and a splint worn on the hand/forearm, housing five surface electrodes. Device delivers constant-voltage symmetrical biphasic Russian waveform stimulation. Microprocessor-controlled switching activates muscles in combinations (cyclic or continuous) for finger/thumb extension and flexion. User selects programs via mode button; intensity adjusted via +/- buttons. Clinician sets maximum current and timing factors via a secured panel. Output displayed on LCD screen. Device powered by rechargeable NiMH batteries. Used by patients to improve hand function and range of motion; helps reduce spasms and atrophy. Benefits include restored active motion and improved circulation in paralyzed limbs.
Clinical Evidence
Bench testing only. Testing included in vitro, biocompatibility, electrical and electromagnetic safety, and software verification and validation to ensure modified device performance is equivalent to predicate devices.
Technological Characteristics
Portable one-channel neuromuscular electrical stimulator. Constant-voltage symmetrical biphasic Russian waveform. Five metal mesh surface electrodes with water-soaked cloth pads. Splint constructed of fiber-reinforced plastic with polyurethane cushions. Powered by rechargeable NiMH batteries. Microprocessor-controlled stimulation switching. LCD graphic display. Connectivity: standalone.
Indications for Use
Indicated for patients with upper limb paralysis due to C5 spinal cord injury or hemiplegia due to stroke requiring maintenance/increase of range of motion, reduction of muscle spasm, prevention/retardation of disuse atrophy, muscle reeducation, or increased local blood circulation.
Regulatory Classification
Identification
An external functional neuromuscular stimulator is an electrical stimulator that uses external electrodes for stimulating muscles in the leg and ankle of partially paralyzed patients (e.g., after stroke) to provide flexion of the foot and thus improve the patient's gait.
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AUG - 8 2003
510(K) SUMMARY
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N.E.S.S. NEUROMUSCULAR ELECTRICAL STIMULATION SYSTEM
# HANDMASTER
## Applicant's Name:
N.E.S.S. Neuromuscular Electrical Stimulation Systems Ltd. 19 Ha-Haroshet Street Kiedar Center, Suite 207 P.O. Box 2500, Industrial Zone Ra'anana 43465 ISRAEL Tel: 011-972-9-7485738 Fax: 011-972-9-7485740
#### Contact Person:
Jonathan S. Kahan, Esq. Hogan & Hartson, L.L.P. Columbia Square 555 Thirteenth Street, NW Washington, DC 20004-1109 Tel: (202) 637-5791 Fax: (202) 637-5910
And/or
Dorit Winitz, Ph. D Push-med Ltd. 117 Ahuzah St. Ra'anana 43373, Israel Tel: 972-9- 7718130 Fax: 972-9-7718131 dorit@push-med.com
# Date Prepared:
June, 2003
Trade Name:
# HANDMASTER
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Classification Name:
Powered muscle stimulators
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Classification:
Class II: Product Code 89IPF: Regulation No. 890.5850.
# Predicate Devices
Neuromuscular Electrical Stimulation Systems Handmaster N.E.S.S. (K952273, K982482, and K010837).
# Device Description:
The Handmaster is a portable, one-channel electrical neuromuscular stimulator for personal use. The stimulator serves five surface electrodes held on to the upper limb by a splint. The control unit housing the stimulator may be worn using the shoulder strap provided, or it may be placed on any stable surface. The splint is worn on the hand and forearm. The splint is connected to the control unit by a light cable.
A single channel of constant-voltage symmetrical biphasic Russian waveform stimulation is delivered to the muscles through five surface electrodes. Microprocessor-controlled switching of the stimulation between these five electrodes allows the muscles to be activated in combinations either cyclically or continuously. The stimulation is ramped up at the beginning and down at the end of each cycle.
The electrode locations allow the Handmaster to give finger and thumb extension and flexion. By pressing the Mode button on the Control Unit, the user can select from seven stimulation programs that comprise either cyclic or continuous activation of the finger and thumb extensors and flexors. In addition to the former light glowing presentation of the active mode, the new LCD screen enables also the presentation of the name of active mode and sub-mode. A continuously changing three and two-bar combination indicates that the stimulation phase is active. A "seventh like" object indicates the stimulation intensity or the battery condition.
The user can increase or decrease the stimulation intensity in ten discrete levels by pressing on buttons labeled "+" or "-" on the control unit. This alters the duration of the stimulation pulse. The intensity is displayed as a number (0 to 9) on a seven-segment like display.
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During the initial system set-up, the clinician opens a screw secured clinical panel within the control unit. Adjustments are provided for limiting the maximum current to the extensor muscles and to the flexor muscles, along with a global timing factor which increases or decreases the duration of the stimulation cycles, effectively speeding or slowing the cyclic hand motion.
The user starts or stops the stimulation program by pressing a "trigger" button. If required, the user may also stop all stimulation immediately by switching OFF the device.
The Handmaster splint is used to hold the wrist joint at a comfortable extension angle (20°), and also to hold the electrodes on the forearm and hand segments. It is constructed from fiber-reinforced plastic with soft polyurethane cushion sections to distribute stress over bony regions. The electrodes are made from metal mesh. Replaceable water-soaked cloth pads are arranged over the electrodes to provide a conductive interface with the skin. A sponge is provided to facilitate wetting of the electrode pads.
Rechargeable nickel-metal-hydride (NiMH) batteries power the device. Battery status can be displayed both during device operation and while recharging the batteries. Both visual and audio battery-low warnings are provided.
# Intended Use:
The Handmaster is intended to be used for the following indications: Maintenance or increase of range of motion, reduction of muscle spasm, prevention or retardation of disuse atrophy, muscle reeducation, and increasing local blood circulation. In patients suffering from upper limb paralysis due to C5 spinal cord injury or hemiplegia due to stroke, it is also intended to provide hand active range of motion and hand function.
# Performance Data & Substantial Equivalence
The Handmaster device is substantially equivalent in all aspects, e.g., technological characteristics, mode of operation, performance characteristics, intended use, etc., to the commercially available Handmaster devices. The principle changes between the devices include:
- Change of the User Control display from 7-Segment display to a ■ graphic display (LCD) and related changes in hardware and software
- 내 Change of the mechanical ON/OFF switch
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- Change in power supply 의
- Limited changes in the external closure 이
- Change of the battery 확
- Change in operating mode combinations 이
- Change in part of the splint materials 미
In vitro, biocompatibility, electrical and electromagnetic testing and verification and validation testing of the software were performed to ensure that the modified HANDMASTER does not raise any new questions of safety and efficacy. Based on these tests results, N.E.S.S Ltd. believes that the modified HANDMASTER is substantially equivalent to the cleared HANDMASTER devices, without raising new safety and/or effectiveness issues.
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DEPARTMENT OF HEALTH & HUMAN SERVICES
Image /page/4/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" around the perimeter. Inside the circle is an abstract symbol that resembles an eagle or bird in flight, composed of three curved lines representing the head, body, and tail.
Public Health Service
AUG - 8 2003
Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850
N.E.S.S. Neuromuscular Electrical Stimulation Systems Ltd. c/o Mr. Jonathan S. Kahan, Esq. Hogan & Hartson, L.L.P. Columbia Square 555 Thirteenth Street, NW Washington, DC 20004-1109
Re: K031900
Trade/Device Name: HANDMASTER Regulation Numbers: 21 CFR 882.5810, 890.5850 Regulation Names: External functional neurolmuscular stimulator, Powered muscle stimulator Regulatory Class: II Product Codes: GZI, IPF, Dated: June 18, 2003 Received: July 9, 2003
Dear Mr. Kahan:
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. 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 (PMA), 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 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 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
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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) 594-4659. 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.
Miriam C. Provost
for Celia M. Witten, Ph.D., M.D. Director Division of General, Restorative and Neurological Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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## INDICATIONS FOR USE
# 510(k) Number (if known):_ KO 3 /900
#### N.E.S.S. Neuromuscular Electrical Stimulation System Device Name: HANDMASTER
#### Indications for Use:
The Handmaster is intended to be used for the following indications: maintenance or increase of range of motion, reduction of muscle spasm, prevention or retardation of disuse atrophy, muscle reeducation, and increasing local blood circulation. In patients suffering from upper limb paralysis due to C5 spinal cord injury or hemiplegic patients due to stroke, it is also intended to provide hand active range of motion and hand function.
(PLEASE DO NOT WRITE BELOW THIS LINE -CONTINUE ON ANOTHER PAGE IF NEEDED)
510(k) Number __
Prescription Use (Per 21 CFR 801.109) OR
Over Use
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Counter
Miriam C. Provost
(Division Sign-Off) Division of General, Restorative and Neurological Devices
\\\PH - 64270/0001 - 12604 v1 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.