Wireless surface EMG

Dynamic analysis of muscle activity and biofeedback in any environment

FREEEMG is a wireless device for surface electromyography (EMG) analysis. Signal accuracy, the absence of wires, the lightness and reduced size of the probes are features enabling users to assess any type of movement, for each body part, without altering the natural movement of the person being tested.

Thousands of centres worldwide use our EMG device in various fields such as: research, sports, occupational medicine, gnathology, neurology and orthopaedics.
FREEEMG is a single system used for multiple purposes: from monitoring to diagnostics and up to injury prevention.

FREEEMG is also available in the H2O version: it is the evolution of BTS technology for EMG analysis specially designed for water measurement.

Thanks to a special protective gel, the electronic components included in the case are completely waterproof and allow the probe to be immersed in water up to a depth of 3 metres (IP68 classification).

The muscle activity evaluation in water can be carried out for both rehabilitative purposes (neuromotor and orthopaedic), and in sports contexts (water sports, indoor training and post-injury recovery). Moreover, to the higher resistance to sweat, the probes are ideal for use in any other sport.

Technical highlights


Up to 20

Battery life

of continuous acquisition

Ultralight probes

13 g

Why choose it

EMG Analysis has never been so quick and easy

Based entirely on wireless technologies, BTS FREEEMG uses up to 20 variable geometry probes for the acquisition and transmission of EMG signals. It also manages probes for the connection of electrogoniometers, allowing the assessment of angles, angular velocities, angular accelerations and footswitches for foot-floor contact area detection. All the probes are easy and quick to recharge by clipping them onto the proprietary probe charger.

Main Features
Technical features
  • Up to 20 probes, selectable among EMG, electrogoniometers and footswitch
  • More than 6 hours of non-stop acquisition
  • Easy and quick to recharge by clipping onto the proprietary probe charger
  • Active and variable geometry electrodes
  • Record of miniaturization weighing only 13 grams.
  • On-board solid-state buffer memory to secure data in case of any WiFi signal loss
  • Up to 20 meters for the data transfer between the probes and the workstation
  • Native integration with BTS motion caputre systems, inertial sensors, force platforms, video cameras.
  • Integration with third-party systems
  • Software for clinical assessment and performance analysis
  • Object-oriented software for the development of customised protocols
  • Development tools

Wireless Probes

Surface electrodes Variable geometry electrodes with snap connectors – 16-bit resolution – acquisition frequency 1KHz
Data transmission Wireless IEEE802.15.4 data transmission (probes – USB receiver) – Real Time
Battery Rechargeable with proprietary charger (snap connector) – lithium-ion polymer
Autonomy Over 6 hours of continuous acquisition
Acquisition range Up to 20 meters (65 feet) in free space (without obstacles)
Holter The solid-state memory allows data storage up to 1 hour and 40 minutes for systems with less than 6 EMG probes, and up to 2 hours for systems with more than 6 EMG probes
Memory On board solid-state buffer memory system
Weight 13 grams (battery included)
Size 41,5×24,8x14mm mother electrode – Ø 16x12mm satellite electrode
Certification Class “IIa”

USB Receiver

EMG channels Up to 10 wireless probes each receiver (no more of 2 receivers allowed)
Weight and size 80 grams – 82x44x22,5mm

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