K983533 · Mini-Mitter Co., Inc. · GWQ · Mar 23, 1999 · Neurology
Device Facts
Record ID
K983533
Device Name
ACTIWATCH
Applicant
Mini-Mitter Co., Inc.
Product Code
GWQ · Neurology
Decision Date
Mar 23, 1999
Decision
SESE
Submission Type
Traditional
Regulation
21 CFR 882.1400
Device Class
Class 2
Indications for Use
The Actiwatch® is designed for documenting physical movements associated with applications in physiological monitoring. The Actiwatch® is intended for the measurement, storage, and analysis of body activity. The Actiwatch® can be attached to the subjects limb or trunk and through the use of an accelerometer, motion is measured, the activity is stored within the device. The Actiwatch® comes with its own software for data processing and display.
Device Story
Actiwatch is a compact, wrist-worn, battery-operated activity monitor; utilizes an internal accelerometer to detect and measure limb or trunk motion; integrates amplitude and speed of motion to produce activity counts; stores data in on-board memory. Device is set up and data is retrieved via a reader interface connected to an IBM-compatible PC running Sleepwatch software. Software programs the device, downloads stored activity counts, displays data, and stores records for analysis. Used by clinicians to document physical movement, analyze circadian rhythms, and score sleep parameters. Provides objective activity data to assist healthcare providers in physiological monitoring and clinical decision-making.
Clinical Evidence
Bench testing only. Sensitivity to motion was validated using a DC motor-driven lever to produce uniform simple harmonic motion; activity counts were compared against calculated maximum acceleration across a range of 0.01 g to 10 g. Inter-device variability was assessed using a sample of five devices, demonstrating minimal variation in the 1G range typical of human movement.
Technological Characteristics
Dimensions: 37x29x9 mm; Weight: 17g. Materials: Titanium frame/battery cover, polycarbonate frame cover, nylon wrist band. Sensing: Accelerometer (sensitivity <0.01 g-force). Energy: CR 2025 coin cell battery. Memory: 16 KB (AW-16) or 64 KB (AW-64). Connectivity: RS-232 serial interface via Actiwatch Reader. Sampling: 2 seconds to 15 minutes. Water resistant.
Indications for Use
Indicated for use as an ultra-compact, lightweight, wrist-worn activity and ambient light monitor to analyze circadian rhythms, automatically collect and score data for sleep parameters, and assess activity in any instance where quantifiable analysis of physical motion is desirable.
Regulatory Classification
Identification
An electroencephalograph is a device used to measure and record the electrical activity of the patient's brain obtained by placing two or more electrodes on the head.
{0}------------------------------------------------
Image /page/0/Picture/0 description: The image shows the date 3/25/99 and the text "Mini-Mitter Co, Inc.". The date is written in a handwritten style, with the month, day, and year separated by forward slashes. The text "Mini-Mitter Co, Inc." is written in a more formal font and is located below the date. The image appears to be a scan of a document.
K9f3533
510(k) Premarket Notification Actiwatch® January 8, 1999
### 10.0 510(K) SUMMARY
10.1 Summary Information
### Submitter's Name and Address 10.1.1
Jack E. McKenzie, Ph.D. Mini-Mitter Co., Inc. P.O. Box 3386
Sunriver, Oregon 97707
Date summary was prepared:
January 8, 1999
## 10.1.2 Name of Device
Trade Name:
Common Name: Classification Name: Actiwatch® Activity Recording Device System, Telemetry, Physiological Signal Conditioner
### 10.1.3 Identification of predicate device
Number K854030 - Wrist Actigraph - Ambulatory Monitoring, Inc. - Product Code GWQ
{1}------------------------------------------------
510(k) Premarket Notification Actiwatch® January 8, 1999
#### 10.1.4 Device Description
#### 10.1.4.1 Functions of the device
The Actiwatch® is a compact, wrist-worn, battery-operated activity monitor whose physical characteristics are similar to a small wristwatch. The monitor consists of the activity monitor itself and a disposable wrist band.
The Actiwatch® is intended for the measurement, storage, and analysis of body activity. The Actiwatch® can be attached to the subject's limb and through the use of an accelerometer, motion of that limb is measured, the activity stored within the activity monitor.
A computer program is used to set un the Actiwatch® to collect data. This program is called Sleepwatch and runs on an IBM-compatible personal computer (PC). The major functions of Sleepwatch are to program the device to collect data, retrieve the data from the activity monitor, display the data, and to store the data for future reference and comparison.
The Actiwatch® Reader is a compact interface device that provides a communications link between the Actiwatch® and the PC. The Actiwatch® Reader is connected to the serial communications port of the PC via a standard 9-conductor RS-232 cable.
#### Basic scientific concepts 10.1.4.2
The Actiwatch® utilizes a motion sensor known as an "accelerometer" to monitor the occurrence and degree of motion. This type of sensor integrates the amplitude and speed of motion and produces a small signal whose magnitude and duration depend on the amount of motion. The activity signals are amplified and digitized by the on-board circuit. This information is stored in memory on board the device as activity counts.
{2}------------------------------------------------
### 10.1.4.3 Pertinent physical characteristics of the Actiwatch ®:
| Parameter | Value |
|---------------------------|------------------------------------------|
| Size | 37x29x9 mm |
| Weight | 17 grams |
| Battery type | CR 2025 coin cell |
| Battery life | 6 months, typical |
| Accelerometer sensitivity | <.01 g-force |
| Frame and battery cover | Titanium |
| Frame cover | Polycarbonate plastic |
| Wrist band | Nylon with buckle |
| Moisture susceptibility | Water resistant |
| Sampling intervals | 2 seconds to 15 minutes |
| Recording time | 1.4 to 365 days, depending upon epoch |
| Memory | 16 KB in AW-16 |
| | 64 KB in AW-64 |
| Storage Temperature | -10 C to 50 C at 0-95% relative humidity |
| Operating Temperature | 0 C to 40 C |
## 10.2 Statement of intended use
The Actiwatch® is designed for documenting physical movements associated with applications in physiological monitoring. The Actiwatch® is intended for the measurement, storage, and analysis of body activity. The Actiwatch® can be attached to the subjects limb or trunk and through the use of an accelerometer, motion is measured, the activity is stored within the device. The Actiwatch® comes with its own software for data processing and display.
{3}------------------------------------------------
510(k) Premarket Notification Actiwatch® January 8, 1999
### 10.2.1 Technological characteristics of this device and predicate device
Both the Actiwatch® and the predicate device, Mini-Motionlogger Actigraph, use an accelerometer to detect accelerated motion in the range 0.01 g and upwards. The Actiwatch® detects motion and measures amount and duration of motion. The Mini-Motionlogger Actigraph is advertised to detect motion and the duration of motion. Each device records data on a computer board and the data can later be downloaded to a PC for analysis and storage. Both devices are battery operated.
#### 10.3 Assessment of Performance Data
#### 10.3.1 Counts vs. motion
The most important performance characteristic of the Actiwatch® is its sensitivity to motion. This characteristic was measured by programming the device to collect data on oneminute intervals. The device was then subjected to a uniform, simple harmonic motion produced by a DC motor moving a lever at a constant speed. From the rotational speed of the motor and the length of the lever arm, the maximum acceleration can be calculated. Activity counts were compared to the maximum acceleration. Attachment No. 1 shows the results of this test. Motion as low as 0.01 g and as large as 10 g can be measured.
#### 10.3.2 Variation between devices
Due to small variations between device characteristics and also due to variations in experimental control, there will be small differences between the activity counts measured with separate devices. These differences have been measured for a sample of five devices. The results are shown in Attachment No. 2. Movement acceleration in the range of 1G is typical for human subjects; this is the region where the Actiwatch® has its smallest variation between devices.
- 27 -
{4}------------------------------------------------
Image /page/4/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo features a stylized eagle with three stripes representing the department's mission. The eagle is encircled by the words "DEPARTMENT OF HEALTH & HUMAN SERVICES • USA" in a circular arrangement.
Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850
MAR 2 3 1999
Jack E. McKenzie, Ph.D. Vice President of Market Development Mini Mitter Company, Inc. P.O. Box 3386 Sunriver, Oregon 97707
Re: K983533 Trade Name: Actiwatch® Regulatory Class: II Product Code: GWQ Dated: January 8, 1999 Received: January 12, 1999
Dear Dr. McKenzie:
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 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 (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. A 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 action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation 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 regulations.
{5}------------------------------------------------
Page 2 - Jack E. McKenzie, Ph.D.
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 regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4595. 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., M.D.
Celia M. Witten, Ph.D., M.D. Director Division of General and Restorative Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
{6}------------------------------------------------
Mini-Mitter Co., Inc.
510(k) Premarket Notification Actiwatch® January 8, 1999
## INDICATIONS FOR USE 2.0
| 510(k) Number (if known): | K983533 |
|---------------------------|------------|
| Device Name: | Actiwatch® |
## Indications for Use:
The Actiwatch® is an ultra-compact, lightweight, wrist-worn activity and ambient light monitor that can be used to analyze circadian rhythms, automatically collect and score data for sleep parameters, and assess activity in any instance where quantifiable analysis of physical motion is desirable.
# (PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NEEDED)
# Concurrence of CDRH, Office of Device Evaluation (ODE)
| Prescription Use | <div> <span> <span style="text-decoration: overline;">X</span> </span> </div> | OR | Over-The-Counter Use | |
|--------------------------|-------------------------------------------------------------------------------|----|----------------------|--|
| (Per 21 CFR 801.109) | | | | |
| (Optional Format 1-2-96) | | | | |

| (Division Sign-Off) |
|-----------------------------------------|
| Division of General Restorative Devices |
K983533510/k) Numbe
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.