Surface EMG

Product Description

Biometrics Ltd EMG sensors and systems have been extensively researched and developed over a number of years incorporating the latest design principles and technologies.

The result is a versatile, state of the art range of EMG products which are reliable, accurate and easy to use.

Full Specifications

When a muscle contracts, electrical activity is generated within the muscle which may be measured using electrodes placed on the surface of the skin. This electrical signal is usually in the order of up to 3,000 micro volts and is referred to as electromyography or EMG.

Biometrics Ltd offer a technologically advanced yet cost effective range of EMG display and data capture systems offering both full portability and real time display and analysis options.

Biometrics sensors and instrumentation are used extensively in the fields of ergonomics, sports science and medical research where measurements of surface EMG are commonly taken for a wide range of applications such as:

  • Symmetry studies during gait
  • Timing data in Biomechanics
  • Work done and fatigue studies
  • Work environment and tool design
  • Sports performance
  • Neuro Rehabilitation
  • Education
  • Veterinary Science

Biometrics Ltd precision bipolar, differential EMG sensors are available in two versions - the SX230 has integral electrodes with a fixed electrode distance of 20mm and the SX230FW that uses disposable electrodes and has a variable electrode distance. Ninety percent of Biometrics Ltd customers use the SX230.

SX230 EMG Sensor

The SX230 is an active probe manufactured by Biometrics Ltd which provides superb quality of signal and ease of use. Unique to the design is the amplifier's input impedance of >10,000,000 M Ohms. This means in practice that little or no skin preparation is required and no conducting gels are required. To use the SX230 EMG sensor simply apply the electrode to the muscle being measured using the die cut medical grade double sided adhesive tape (part no. T350). The quality of the signal received is excellent for both static and dynamic applications.

The SX230 EMG sensor is extremely versatile, readily connecting to the portable DataLOG system and the tethered DataLINK system and K800 general purpose amplifier.

All three of these instruments can be used to:

  • Collect and display the EMG data
  • Integrate the EMG data with data from other sensors
  • Synchronise the EMG data with third party systems such as
    • Video motion capture such as Vicon, Qualysis, and Peak Performance
    • 3D force plate systems such as Kistler and AMTI

As well as recording the EMG data, both the DataLOG and DataLINK systems provide software to software communication in real time via the included Microsoft Dynamic Link Library. This means that your EMG data can be collected in real time in third party software with a minimum amount of programming.

The DataLINK system and K800 amplifier can be interfaced to third party hardware, such as National Instruments A to D cards via the R2000i Analogue output cable.

When using the SX230 EMG sensor with any Biometrics Ltd instrument, independent of the number of EMG sensors used at any one time, only one of the following ground reference cables is required:

R506 has a standard 4mm snap connector and comes with convenient elasticated wrist bands for ease of use. The R506 may also be used with proprietary reusable or disposable electrodes having a 4mm snap (part no. SEN3001).

R306 comes with a standard 2mm spring plug for connection to proprietary disposable electrodes with a 2mm spring socket.

The new Biometrics Ltd Analysis Software version 8.51 is one of the most powerful yet cost effective EMG display and analysis software tools available. The most commonly used EMG data analysis is included -Rectify, RMS, EMG Work Done, Integration, Mean frequency, Median frequency, Power frequency. Biometrics Ltd Analysis Software version 8.51 is compatible with Windows 7, Windows Vista and Windows XP operating systems.

SX230FW EMG Amplifier

For applications where variable inter-electrode distance is desired, the SX230FW EMG Amplifier has the same superb signal pickup of the SX230. Instead of the integral electrodes of the SX230, the SX230FW has two flying wire leads for use with any reusable or disposable SEMG electrode incorporating a 4 mm snap. The maximum inter-electrode distance is 170 mm and the minimum distance is dependent upon the size of the electrodes used.

The SEN3001 surface EMG electrode may be used with the SX230FW. The SEN3001 is a small (22 x 28 mm) silver/silver chloride EMG electrode designed for single or multiple applications to the same patient/subject.

EMG GraphThe SX230 is an active EMG sensor designed and manufactured by Biometrics and has been developed with ease of use and superb quality of signal in mind.

The SX230 may readily connect to either the DataLOG, DataLINK or K800. These instruments are general purpose data collection devices and may collect signals from a wide range of sensors simultaneously with EMG. This is ideal for correlation of muscle activity with other physiological parameters.

Using the DataLOG or DataLINK the stored data may be displayed and analyzed within the Biometrics software, or the raw data may be saved as an ASCII or a standard Sound Wave file for import into many other analysis programs such as Microsoft Excel or Cool Edit. Extensor EMG and 3 repetitions of maximum grip strengthAlternatively the DataLOG and DataLINK systems can transfer data in real time via the Microsoft Dynamic Link Library to any software capable of receiving data by the Microsoft Dynamic Link Library.

The contact switch assembly type no. FS4 is readily interfaced to both the DataLOG and DataLINK giving the user the ability for example to monitor heel contact and toe off during EMG gait trials.

Graphs showing extensor EMG and 3 repetitions of maximum grip strength of a normal subject. Please note this EMG trace is the raw data and NO FILTERING HAS BEEN APPLIED to reduce apparent artefacts. Data collected using DataLINK, active EMG sensor SX230 and hand dynamometer G100.

EMG and the DataLOG

The DataLOG offers the user the ability to collect EMG and other data reliably from up to 24 channels simultaneously in a truly portable configuration. When more than 8 channels are required 2 or 3 DataLOGs may be synchronised using a single wireless Bluetooth connection providing options for 16 and 24 analog channels. The DataLOG Display and Analysis software allows for an unlimited number of real date and time stamped data files to be opened simultaneously, and the time axis may be tracked across all files allowing display and analysis for a large number of channels.

The capabilities offered to the user of EMG measurements using the DataLOG is unrivalled even by much more costly systems.

EMG and the DataLINK

The DataLINK provides the user the ability to collect EMG and other data simultaneously with real time display and real time data analysis. The usefulness and simplicity of this accurate real time display and real time feedback is emphasized for both a research and educational setting.

The DataLINK Display and Analysis software allows for:

  • 8 analog channels and 5 digital channels to be displayed and analyzed real time
  • real time display and real time scaling in engineering or SI units
  • adjustable real time audible and visual alarms for any channel
  • 8, 16 or 24 analog channels
  • Readily synchronised with other systems