510(k) · Cleared
ClearedNon-Contact Tonometer, Model NT-4000
Data to Oct 25, 2026 (FDA decisions) Oct 12, 2026 (recalls) Sep 30, 2026 (MAUDE) refreshed weekly
Nidek, Inc. · HKX Tonometer, Ac-Powered
Cleared on Dec 4, 2003 as substantially equivalent to K913189 (Nidek, Inc., 1991) after a 183-day review. Its family tree reaches back 1 generation to 1991.
- Decided
- Dec 4, 2003
- Review
- 183 days
- Class
- Class II
- Product code
- HKX
- Recalls
- None
- Predicates
- 1
Its longest line of descent runs back 1 generation to K913189 (1991). No later device cites it as a predicate yet.
- Root · 1 generation backK913189 Nidek Model NT-1000Nidek, Inc. · 1991
- This deviceK031733 Non-Contact Tonometer, Model NT-4000Nidek, Inc. · 2003
View FIG. 1 as a table
Line of descent and top descendants
| Generation | Number | Device | Applicant | Decided | Recalls |
|---|---|---|---|---|---|
| −1 | K913189 | Nidek Model NT-1000 | Nidek, Inc. | 1991 | — |
| 0 (this device) | K031733 | Non-Contact Tonometer, Model NT-4000 | Nidek, Inc. | 2003 | — |
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 HKX? 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 HKX device
- #1 K253039 Auto Kerato-Refracto Tonometer TRK-3 Omniascore 11.5 · 5 generations · no Class I recall
- #2 Held for the reportin the report
What was it cleared against? (1)
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 |
|---|---|---|---|
| * | K913189 | Nidek Model NT-1000Summary page 1…predicate device: Predicate Device Manufacturer 510(k) No. Date Cleared Model NT-1000 Non- Nidek Co. Ltd. K913189 October 15, Contact Tonometer 1991… | 1991 |
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?
- Its one ancestor has no recall.
- 1 other device also cites its predicate K913189.
How does its category compare?
All HKX devicesHKX Tonometer, Ac-Powered: FDA decisions, review times, recalls and adverse event reports over 20 years.
FDA decisions per year · HKX
1in 2025
2026 to Oct 25, outlined.
Median 510(k) review, days · HKX
290in 2019
Receipt to decision; years with fewer than 3 clearances left blank.
Recalls per year · HKX
No recall names HKX since 2007.
Adverse event reports per year · HKX
1in 2015
MAUDE reports naming product code HKX, 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 | 0 | — | 0 | 0 |
| 2008 | 2 | — | 0 | 1 |
| 2009 | 1 | — | 0 | 0 |
| 2010 | 1 | — | 0 | 1 |
| 2011 | 1 | — | 0 | 0 |
| 2012 | 1 | — | 0 | 0 |
| 2013 | 0 | — | 0 | 0 |
| 2014 | 0 | — | 0 | 0 |
| 2015 | 1 | — | 0 | 1 |
| 2016 | 0 | — | 0 | 0 |
| 2017 | 1 | — | 0 | 0 |
| 2018 | 1 | — | 0 | 0 |
| 2019 | 3 | 290 | 0 | 0 |
| 2020 | 0 | — | 0 | 0 |
| 2021 | 0 | — | 0 | 0 |
| 2022 | 0 | — | 0 | 0 |
| 2023 | 1 | — | 0 | 0 |
| 2024 | 0 | — | 0 | 0 |
| 2025 | 1 | — | 0 | 0 |
| 2026 | 0 | — | 0 | — |
What is it indicated for?
The Nidek Model NT-4000 is a non-contact tonometer that is indicated for use in the measurement of intraocular pressure of the human eye.
Indications for use as stated in the FDA summary.
https://510kreport.com/device/K031733 · printed Nov 5, 2026
Cite this page
510(k) Report. “K031733: Non-Contact Tonometer, Model NT-4000.” Lineage record from FDA 510(k) data and the FDA summary. Updated Nov 3, 2026. Accessed Nov 5, 2026. https://510kreport.com/device/K031733
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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