510(k) · Cleared
ClearedHandmaster
Data to Oct 25, 2026 (FDA decisions) Oct 12, 2026 (recalls) Sep 30, 2026 (MAUDE) refreshed weekly
Ness-Neuromuscular Electrical Stimulation Systems · GZI Stimulator, Neuromuscular, External Functional
Cleared on Aug 8, 2003 as substantially equivalent to K952273 (Neuromusclar Electrical Stimulation Systems, Ltd., 1996) and 2 other predicates after a 50-day review. Its family tree reaches back 3 generations to 1981. 35 later devices descend from it.
- Decided
- Aug 8, 2003
- Review
- 50 days
- Class
- Class II
- Product code
- GZI
- Recalls
- None
- Predicates
- 3
Its longest line of descent runs back 3 generations to K813008 (1981). 6 ancestors in all. 35 later devices descend from it, 1 citing it directly.
- Root · 3 generations backK813008 Respond II...Neuromuscular StimulatorMedtronic Vascular · 1981
- 2 generations backK952273 Handmaster NMS1Neuromusclar Electrical Stimulation Systems, Ltd. · 1996
- 1 generation backK982482 Handmaster NMS1N.E.S.S. Nuromuscular Electrical Stimulation Syst · 1998
- This deviceK031900 HandmasterNess-Neuromuscular Electrical Stimulation Systems · 2003
- Descendant · cites it directly · 34 of its ownK080950 Stiwell MED4Otto Bock, Austria GmbH · 2009
- Descendant · 2 generations on · 21 of its ownK110179 IncontrolIncontrol Medical, LLC · 2012
- Descendant · 3 generations on · 10 of its ownK134020 IntonemvIncontrol Medical, LLC · 2014
- Descendant · 3 generations on · 9 of its ownK141158 APEXIncontrol Medical, LLC · 2014
- Descendant · 4 generations on · 6 of its ownK181497 HPM-6000UFBTL Industries, Inc. · 2018
Showing 5 of 35 descendants. See all descendants
Descendants cleared per year
Most influential descendants
Showing 5 of 35 · See all- K080950Stiwell MED4Otto Bock, Austria GmbH · 2009 · cites it directly34descendants
- K110179IncontrolIncontrol Medical, LLC · 2012 · 2 generations on21descendants
- K134020IntonemvIncontrol Medical, LLC · 2014 · 3 generations on10descendants
- K141158APEXIncontrol Medical, LLC · 2014 · 3 generations on9descendants
- K181497HPM-6000UFBTL Industries, Inc. · 2018 · 4 generations on6descendants
View FIG. 1 as a table
Line of descent and top descendants
| Generation | Number | Device | Applicant | Decided | Recalls |
|---|---|---|---|---|---|
| −3 | K813008 | Respond II...Neuromuscular Stimulator | Medtronic Vascular | 1981 | — |
| −2 | K952273 | Handmaster NMS1 | Neuromusclar Electrical Stimulation Systems, Ltd. | 1996 | — |
| −1 | K982482 | Handmaster NMS1 | N.E.S.S. Nuromuscular Electrical Stimulation Syst | 1998 | — |
| 0 (this device) | K031900 | Handmaster | Ness-Neuromuscular Electrical Stimulation Systems | 2003 | — |
| +1 | K080950 | Stiwell MED4 | Otto Bock, Austria GmbH | 2009 | — |
| +2 | K110179 | Incontrol | Incontrol Medical, LLC | 2012 | — |
| +3 | K134020 | Intonemv | Incontrol Medical, LLC | 2014 | — |
| +3 | K141158 | APEX | Incontrol Medical, LLC | 2014 | — |
| +4 | K181497 | HPM-6000UF | BTL Industries, Inc. | 2018 | — |
Other ancestors by year cleared
| Year cleared | Devices | With a Class I recall |
|---|---|---|
| 1986 | 1 | 0 |
| 1987 | 1 | 0 |
| 2001 | 1 | 0 |
Descendants by year cleared
| Year cleared | Devices | With a Class I recall |
|---|---|---|
| 2009 | 1 | 0 |
| 2012 | 1 | 0 |
| 2014 | 3 | 0 |
| 2015 | 4 | 0 |
| 2018 | 2 | 0 |
| 2019 | 2 | 0 |
| 2020 | 3 | 0 |
| 2021 | 1 | 0 |
| 2022 | 3 | 0 |
| 2023 | 4 | 0 |
| 2024 | 1 | 0 |
| 2025 | 5 | 0 |
| 2026 | 5 | 0 |
Sources: FDA 510(k) database (decision fields), the FDA summary (predicates and indications), FDA recall and enforcement reports, and MAUDE; processed by 510(k) Report. Verify on FDA.gov · Methodology and accuracy.
Planning a device in GZI? A 510(k) Report weighs predicate choices, recall history and review times for a new device like this one.
Top candidate predicates for a new GZI device
- #1 K243828 Cionic Neural Sleeve (NS-200)score 12.9 · 13 generations · no Class I recall
- #2 Held for the reportin the report
- #3 Held for the reportin the report
What was it cleared against? (3)
Devices the submitter claimed this one is substantially equivalent to (*), and reference devices cited for a specific test or feature (†), as written in the FDA summary.
| Type | Number | Device | Decided |
|---|---|---|---|
| * | K952273 | Handmaster NMS1Summary page 2…ss 11; Product Code 89IPF; Regulation No. 890.5850. Predicate Devices N.E.S.S. Neuromuscular Electrical Stimulation Systems Handmaster (K952273, K982482, and K010837). Device Description: The Handmaster is a portable, one-channel electrical neuromuscular stimulator for… | 1996 |
| * | K982482 | Handmaster NMS1Summary page 2…oduct Code 89IPF; Regulation No. 890.5850. Predicate Devices N.E.S.S. Neuromuscular Electrical Stimulation Systems Handmaster (K952273, K982482, and K010837). Device Description: The Handmaster is a portable, one-channel electrical neuromuscular stimulator for personal… | 1998 |
| * | K010837 | HandmasterSummary page 2…IPF; Regulation No. 890.5850. Predicate Devices N.E.S.S. Neuromuscular Electrical Stimulation Systems Handmaster (K952273, K982482, and K010837). Device Description: The Handmaster is a portable, one-channel electrical neuromuscular stimulator for personal use. The stim… | 2001 |
What descends from it? (35)
See all 351 later device cites it directly; ranked here by how many devices descend from each in turn.
| Number | Device | Decided | Descendants |
|---|---|---|---|
| K080950 | Stiwell MED4 | 2009 | 34 |
Has anything in its family been recalled? (0 Class I)
No FDA recall names this device.
No ancestor or descendant has a Class I recall.
What does this lineage say?
- The line of descent spans 22 years and passes through 4 companies; a new generation was cleared every 4.9 years on median.
- None of the 6 ancestors has a recall.
- Of its descendants, K080950 (Otto Bock, Austria GmbH, 2009) has gone furthest, with 34 descendants of its own.
- 3 other devices also cite its predicate K952273.
How does its category compare?
All GZI devicesGZI Stimulator, Neuromuscular, External Functional: FDA decisions, review times, recalls and adverse event reports over 20 years.
FDA decisions per year · GZI
2in 2025
2026 to Oct 25, outlined.
Median 510(k) review, days · GZI
110in 2022
Receipt to decision; years with fewer than 3 clearances left blank.
Recalls per year · GZI
1in 2008
Class I (0 since 2007) Class II/III not classified
Adverse event reports per year · GZI
3in 2025
MAUDE reports naming product code GZI, not matched to any one device; reports are not rates.
View these four charts as a table
| Year | Decisions | Median 510(k) review, days | Recalls (Class I) | MAUDE reports |
|---|---|---|---|---|
| 2007 | 4 | 81 | 0 | 1 |
| 2008 | 1 | — | 1 | 2 |
| 2009 | 1 | — | 0 | 8 |
| 2010 | 0 | — | 0 | 1 |
| 2011 | 6 | 139 | 0 | 3 |
| 2012 | 2 | — | 0 | 2 |
| 2013 | 2 | — | 0 | 0 |
| 2014 | 3 | 299 | 0 | 2 |
| 2015 | 1 | — | 0 | 3 |
| 2016 | 1 | — | 0 | 0 |
| 2017 | 6 | 168 | 0 | 2 |
| 2018 | 2 | — | 0 | 1 |
| 2019 | 2 | — | 0 | 4 |
| 2020 | 2 | — | 0 | 0 |
| 2021 | 1 | — | 0 | 1 |
| 2022 | 4 | 110 | 0 | 3 |
| 2023 | 1 | — | 0 | 1 |
| 2024 | 2 | — | 0 | 1 |
| 2025 | 2 | — | 0 | 3 |
| 2026 | 0 | — | 0 | — |
What is it indicated for?
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,
Indications for use as stated in the FDA summary.
https://510kreport.com/device/K031900 · printed Nov 6, 2026
Cite this page
510(k) Report. “K031900: Handmaster.” Lineage record from FDA 510(k) data and the FDA summary. Updated Nov 3, 2026. Accessed Nov 6, 2026. https://510kreport.com/device/K031900
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Record history
- FDA decision record loaded May 2, 2026
- Summary read Oct 13, 2026 (extraction version 9eaa42aa01ed)
- Lineage and recalls computed Nov 3, 2026
- Page last updated Nov 3, 2026