510(k) · Cleared
ClearedLow-frequency Stimulator (Model: AST-645, AST-646)
Data to Oct 25, 2026 (FDA decisions) Oct 12, 2026 (recalls) Sep 30, 2026 (MAUDE) refreshed weekly
Shenzhen Osto Technology Co., Ltd. · NUH Stimulator, Nerve, Transcutaneous, Over-The-Counter
Cleared on Nov 22, 2021 as substantially equivalent to K191151 (Jkh USA, LLC, 2019) and 1 other predicate after a 63-day review. Its family tree reaches back 9 generations to 1988.
- Decided
- Nov 22, 2021
- Review
- 63 days
- Class
- Class II
- Product code
- NUH
- Recalls
- None
- Predicates
- 2
Its longest line of descent runs back 9 generations to K881114 (1988). 62 ancestors in all, the oldest K872976 (1987). No later device cites it as a predicate yet.
- Root · 9 generations backK881114 Empi Model 989, TensEmpi · 1988
- 5 generations between
- 3 generations backK140333 AscendNeurometrix, Inc. · 2014
- 2 generations backK182203 JKH Stimulator PlusJkh USA, LLC · 2019
- 1 generation backK191151 JKH Stimulator PlusJkh USA, LLC · 2019
- This deviceK212989 Low-frequency Stimulator (Model: AST-645, AST-646)Shenzhen Osto Technology Co., Ltd. · 2021
Show all 9 generations
- Root · 9 generations backK881114 Empi Model 989, TensEmpi · 1988
- 8 generations backK970203 Epix VTEmpi · 1997
- 7 generations backK061650 Select Tens, Model 4600SEmpi · 2007
- 6 generations backK090922 Empi Active Transcutaneous Nerve StimulatorEmpi · 2009
- 5 generations backK121184 SensusNeurometrix, Inc. · 2012
- 4 generations backK130919 SensusNeurometrix, Inc. · 2013
- 3 generations backK140333 AscendNeurometrix, Inc. · 2014
- 2 generations backK182203 JKH Stimulator PlusJkh USA, LLC · 2019
- 1 generation backK191151 JKH Stimulator PlusJkh USA, LLC · 2019
- This deviceK212989 Low-frequency Stimulator (Model: AST-645, AST-646)Shenzhen Osto Technology Co., Ltd. · 2021
View FIG. 1 as a table
Line of descent and top descendants
| Generation | Number | Device | Applicant | Decided | Recalls |
|---|---|---|---|---|---|
| −9 | K881114 | Empi Model 989, Tens | Empi | 1988 | — |
| −8 | K970203 | Epix VT | Empi | 1997 | — |
| −7 | K061650 | Select Tens, Model 4600S | Empi | 2007 | — |
| −6 | K090922 | Empi Active Transcutaneous Nerve Stimulator | Empi | 2009 | — |
| −5 | K121184 | Sensus | Neurometrix, Inc. | 2012 | — |
| −4 | K130919 | Sensus | Neurometrix, Inc. | 2013 | — |
| −3 | K140333 | Ascend | Neurometrix, Inc. | 2014 | — |
| −2 | K182203 | JKH Stimulator Plus | Jkh USA, LLC | 2019 | — |
| −1 | K191151 | JKH Stimulator Plus | Jkh USA, LLC | 2019 | — |
| 0 (this device) | K212989 | Low-frequency Stimulator (Model: AST-645, AST-646) | Shenzhen Osto Technology Co., Ltd. | 2021 | — |
Other ancestors by year cleared
| Year cleared | Devices | With a Class I recall |
|---|---|---|
| 1987 | 1 | 0 |
| 1988 | 2 | 0 |
| 1991 | 2 | 0 |
| 1992 | 2 | 0 |
| 1993 | 2 | 0 |
| 1994 | 2 | 0 |
| 1995 | 1 | 0 |
| 1996 | 2 | 0 |
| 1997 | 2 | 0 |
| 1998 | 3 | 0 |
| 1999 | 2 | 0 |
| 2000 | 1 | 0 |
| 2002 | 2 | 0 |
| 2003 | 3 | 0 |
| 2004 | 2 | 0 |
| 2005 | 3 | 0 |
| 2007 | 3 | 0 |
| 2009 | 1 | 0 |
| 2010 | 1 | 0 |
| 2011 | 2 | 0 |
| 2012 | 3 | 0 |
| 2013 | 4 | 0 |
| 2014 | 2 | 0 |
| 2016 | 3 | 0 |
| 2017 | 1 | 0 |
| 2020 | 1 | 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 NUH? 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 NUH device
- #1 K190783 Health Expert Electronic Stimulator (model…score 15.8 · 7 generations · no Class I recall
- #2 Held for the reportin the report
- #3 Held for the reportin the report
What was it cleared against? (2)
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 |
|---|---|---|---|
| * | K191151 | JKH Stimulator PlusSummary page 4…Primary Predicate Devic Information ♦ Sponsor Jkh Usa, LLC ♦ Device Name and Model JKH Stimulator Plus ♦ 510(k) Number K191151 Page 1 of 8 ♦ Product Code NUH, NGX, NYN,… | 2019 |
| * | K190783 | Health Expert Electronic Stimulator (model: AST-300L)Summary page 5…Shenzhen OSTO Technology Company Limited ♦ Device Name and Model Health Expert Electronic Stimulator (Model: AST-300L) ♦ 510(k) Number K190783 ♦ Product Code NUH, NGX ♦ Regulation Number 882.5890, 890.5850 ♦ Regulation Class… | 2020 |
What descends from it?
No later submission names this one as a predicate yet.
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 33 years and passes through 4 companies; a new generation was cleared every 2.4 years on median.
- 1 of the 62 ancestors has a recall of any class.
- 2 other devices also cite its predicate K191151.
How does its category compare?
All NUH devicesNUH Stimulator, Nerve, Transcutaneous, Over-The-Counter: FDA decisions, review times, recalls and adverse event reports over 20 years. 2021, this device’s year, is highlighted.
FDA decisions per year · NUH
15in 2025
2026 to Oct 25, outlined.
Median 510(k) review, days · NUH
119in 2025
Receipt to decision; years with fewer than 3 clearances left blank.
Recalls per year · NUH
No recall names NUH since 2007.
Adverse event reports per year · NUH
7in 2025
MAUDE reports naming product code NUH, 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 | 161 | 0 | 0 |
| 2008 | 0 | — | 0 | 0 |
| 2009 | 1 | — | 0 | 0 |
| 2010 | 3 | 148 | 0 | 0 |
| 2011 | 6 | 231 | 0 | 0 |
| 2012 | 6 | 170 | 0 | 0 |
| 2013 | 10 | 189 | 0 | 1 |
| 2014 | 16 | 212 | 0 | 9 |
| 2015 | 14 | 198 | 0 | 11 |
| 2016 | 13 | 145 | 0 | 13 |
| 2017 | 17 | 155 | 0 | 21 |
| 2018 | 16 | 121 | 0 | 18 |
| 2019 | 19 | 213 | 0 | 5 |
| 2020 | 14 | 147 | 0 | 8 |
| 2021 | 14 | 198 | 0 | 7 |
| 2022 | 20 | 103 | 0 | 2 |
| 2023 | 15 | 127 | 0 | 4 |
| 2024 | 20 | 90 | 0 | 7 |
| 2025 | 15 | 119 | 0 | 7 |
| 2026 | 5 | 137 | 0 | — |
What is it indicated for?
TENS:
To be used for temporary relief of pain associated with sore and aching muscles in the shoulder, waist, back, back of the neck, arm, leg, and foot due to strain from exercise or normal household work activities by applying current to stimulate nerve.
It is also intended for symptomatic relief and management of chronic, intractable pain and relief of pain associated with arthritis.
PMS:
It is intended to stimulate healthy muscles in order to improve and facilitate muscle performance.
Heating:
It is intended for temporary relief of minor aches and pains.
Indications for use read by OCR from a scanned FDA summary, so letters may be misread. Check the PDF before quoting it.
https://510kreport.com/device/K212989 · printed Nov 6, 2026
Cite this page
510(k) Report. “K212989: Low-frequency Stimulator (Model: AST-645, AST-646).” Lineage record from FDA 510(k) data and the FDA summary. Updated Nov 3, 2026. Accessed Nov 6, 2026. https://510kreport.com/device/K212989
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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