RESEARCH-GRADE WEARABLE SENSORS

THE OPAL

a research-grade wearable sensor built for ultimate control

• High sampling rate

• Stream to MATLAB, Java, Python, C

• Access raw kinematic data

• Sync with other systems

• 8-16 hours battery life

• Up to 24 Opals on one network

• Stream or log data

• Gyroscope + accelerometer

FOUNDATIONAL TECHNOLOGY

The Opal is the foundational technology in all of our solutions.

While you can customize a system of any size, we have some standard solutions to choose from:

Motion Studio: This is our free data acquisition software, perfect for those who want to develop their own protocols and algorithms. Keep scrolling to learn more about this solution.

Mobility Lab: This is for those who want to measure spatial/temporal gait and balance. By far our most popular system, find out more in the Gait & Balance tab above.

Moveo Explorer: Our newest product, it is for those who want to measure full body kinematics in unconstrained environments. Interested in automated joint angle analysis? Learn more in the Kinematics tab above.

Wireless synchronization

Up to 24 Opals in one wireless network with precise time synchronization.

Record natural movement

Small, silent, and wireless means the subject will wear it and forget it – recording natural movement all day long.

Real-time Results

Continuously stream data for real-time processing with a latency less than 30ms, perfectly tuned for biofeedback applications.

Never Lose Data

Over 30 days of kinematic data can be stored on each Opal.

Long battery life

16 hours of battery life while logging data and more than 8 hours while streaming data, Opals beat the competition by 4x.

Use Anywhere

Break out of the lab and record movement on the field of play, at home, or anywhere.

OPAL VIDEO

PUBLICATIONS

Opal Wearable Sensors have been featured in hundreds peer reviewed publications.

STREAM

Stream data in real time to a local computer

LOG

Log data on board each Opal and download later

TECH SPECS

Sensor Characteristics

	Accelerometers (2)	Gyroscope	Magnetometer
Axes	3 axes	3 axes	3 axes
Range	± 16g, ± 200g	± 2000 deg/s	± 8 Gauss
Noise	120 μg/√Hz, 5 mg/√Hz	0.025 deg/s/√Hz	2 mGauss/√Hz
Sample Rate¹	20 to 128 Hz	20 to 128 Hz	20 to 128 Hz
Bandwidth	50 Hz	50 Hz	32.5 Hz
Resolution	14 bits, 17.5 bits	16 bits	12 bits

¹ Adjustable, up to 24 Opals

Hardware Characteristics


Dimensions	43.7 x 39.7 x 13.7 mm (LxWxH)
Weight	< 25 grams (with battery)
Material	PC-ABS Plastic, Glass
Internal Storage	8 Gb (~720h Storage)
Battery Life	Synchronous Logging: 12h, Asynchronous Logging: 16h

Wireless Characteristics


Wireless Radio	Nordic Semiconductor nRFL01 + radio, ultra low power
Frequency Band	2.40-2.48GHz ISM band, adjustable
Data Rate	2Mbps on-air data rate
Latency*	300ms (typical) with data buffer, 30ms (typical) without data buffer
Transmission Range	30m line of sight, 10m indoors
Data Buffer	8Gb (~720 hours)
Synchronization	≤1ms difference, up to 24 Opals
Bluetooth^2	No
Wifi^2	No

* Latency is defined as the time when sample is recorded on the Opal, to the time it is emitted from the host libraries. Our latency includes the hardware, firmware, USB and host library stack.

Both WiFi and Bluetooth use too much energy to be used in small wireless system like the Opal. Our battery life would significantly decrease if we chose to support these wireless protocols, even Bluetooth low energy. Other low power radios, like Zigbee, do not have the bandwidth required to transmit 10 data channels.

Orientation Estimates


Static Accuracy (Roll/Pitch)	1.15 deg
Static Accuracy (Heading)	1.50 deg
Dynamic Accuracy	2.80 deg

Accessories

Access Point

The Access Point is the wireless communication hub between the host computer and Opal wearable sensors.

Docking Station

The docking station is used to configure, charge, and download any logged data from our wearable sensors.

Sensor Straps

We offer multiple elastic straps that adjust to fit every body size.

Software

Motion Studio

Motion Studio is the default software suite bundled with any purchase. It also provides advanced configuration, recording, real-time visualization, calibration, and data management features.

Mobility Lab

Mobility Lab is a portable gait and balance system that provides sensitive, valid, and reliable outcome measures.

Synchronization

Master Synchronization

In a master wireless synchronization scheme, up to 24 Opals in a wireless network transmits kinematic data wirelessly to one or more access point. One of the access points, which is identified during configuration, becomes the master timing source for the entire network. The access point synchronization signal is used to precisely time the transmission of a synchronization data packet. This data packet is transmitted at the exact same time by all access points and is received by all Opals in the wireless network.

Mesh Synchronization

In the mesh synchronization scheme, there is no master time source. Instead, each device in the network sends a synchronization packet during its prescribed time slot, enabling each device to compare its clock against the clock of each of the other Opals in the wireless network. This comparison allows each Opal in the mesh to create a statistical model of the network time-a distributed statistical clock model-and of its own clock relative to the network time.

Third-Party Synchronization

You can easily synchronize your Opal inertial measurement units with third-party systems, such as optical motion capture systems, EMG, or gait mats. Access Points come fitted with a 6 pin digital I/O connector and a 4 pin analog I/O connector.