(166 days)
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.
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. 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.
The Mini-Mitter Co., Inc. Actiwatch® 510(k) submission [K983533] describes a device developed for measuring, storing, and analyzing body activity. The primary study presented focuses on the device's sensitivity to motion and inter-device variation rather than a clinical effectiveness study with human subjects.
Here's a breakdown of the requested information based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state formal "acceptance criteria" for performance that would typically be seen in more recent FDA submissions (e.g., minimum sensitivity, specificity, or accuracy percentages). Instead, it describes performance characteristics that were measured and compared to the predicate device.
| Performance Characteristic | Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|---|
| Motion Sensitivity | Detect motion in the range of 0.01g and upwards (similar to predicate device). | Motion as low as 0.01g and as large as 10g can be measured. |
| Inter-device Variation | Small differences between activity counts across devices, especially in typical human motion range (1G). | Smallest variation between devices in the 1G movement acceleration range (typical for human subjects). |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set:
- Motion Sensitivity: Not explicitly stated as a number of devices or repetitions. The test involved "programming the device to collect data on one-minute intervals" and then subjecting "the device" to uniform simple harmonic motion. It appears to be a single device test or representative test of the device model's capability. Attachment No. 1 would likely provide more details, but it is not included in the provided text.
- Inter-device Variation: A sample of five devices was used.
- Data Provenance: The tests described appear to be conducted in a laboratory setting by the manufacturer, Mini-Mitter Co., Inc., for the purpose of demonstrating device performance. This would be considered retrospective in the context of the 510(k) submission, as the data was collected prior to market approval. The country of origin of the data is not explicitly stated but can be inferred as the USA, where the company is located.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
This type of study did not involve human experts establishing ground truth. The assessments were technical performance measurements against known physical inputs:
- Motion Sensitivity: Ground truth was established by calculation from the physical setup – "From the rotational speed of the motor and the length of the lever arm, the maximum acceleration can be calculated." This is an objective, deterministic ground truth, not requiring human expert interpretation.
- Inter-device Variation: Ground truth was the controlled, known input motion applied to the devices, and the "ground truth" for comparison was the consistency of the readings among the devices.
4. Adjudication Method for the Test Set
Not applicable, as no human expert adjudication was involved in establishing the ground truth for these technical performance tests.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, an MRMC comparative effectiveness study was not done. The submission focuses on the standalone performance characteristics of the device and its substantial equivalence to a predicate device, not on comparing human reader performance with and without AI assistance.
6. If a Standalone (i.e., Algorithm Only Without Human-in-the-Loop Performance) Was Done
Yes, the studies described are standalone performance assessments of the Actiwatch® device.
- The "Counts vs. motion" test assesses the device's ability to accurately measure motion (algorithm and hardware combined) against a physically controlled input.
- The "Variation between devices" test assesses the consistency of the device's measurements across different units.
Both are focused purely on the device's inherent performance.
7. The Type of Ground Truth Used
- Motion Sensitivity: Objective, physically calculated maximum acceleration based on a controlled mechanical setup (simple harmonic motion).
- Inter-device Variation: Controlled, known input motion (implicitly, the same motion applied to all five devices). The "ground truth" here is the expectation of consistent readings for a given input.
8. The Sample Size for the Training Set
The document does not describe the use of a "training set" in the context of machine learning, as this device (from 1999) predates widespread use of AI/ML in medical devices requiring such sets. The Actiwatch® utilizes an accelerometer and on-board circuitry to amplify and digitize signals, storing them as "activity counts." This is a deterministic signal processing approach, not a learned algorithm.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as no training set for a machine learning algorithm was used.
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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
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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.
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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.
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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.
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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.
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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
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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 | X | 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
§ 882.1400 Electroencephalograph.
(a)
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.(b)
Classification. Class II (performance standards).