Biometrics DataLINK/DataLOG EMG Sensors

The SX230 is a pre amplifier designed and manufactured by Biometrics and has been developed with ease of use and superb quality of signal in mind. Unique to the design is the Input Impedance of >10,000,000 M Ohms. What this means in practise is that little or no skin preparation and no gels or creams are required, yet the quality of the signal recorded is absolutely superb for both static and dynamic applications.

Simply apply the electrodes over the body of the small or large muscles being measured using the die cut medical grade double sided adhesive tape (part no. T350). Independent of the number of active EMG sensors being used at any one time, only one ground reference cable is required.

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 200 mm and the minimum distance is dependent upon the size of the electrodes used.

SEN3001 EMG Electrode

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.

Ground Cables

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

R506 (or R606 with metal connector) comes with a standard 4 mm snap connector to use with proprietary reusable or disposable electrodes with a 4 mm snap.

The preamplifiers are attached to either the DataLOG or DataLINK and the EMG default settings are chosen within the Management software. EMG raw data is collected and analysed within the analysis software.

The DataLOG provides a fully portable system with built in adjustable audible alarms per channel. The DataLINK provides in depth real time display and analysis with adjustable audible alarms per channel.

Active Surface EMG Amplifier
(Part # SX230) Specifications

Electrodes: Integral dry reusable
Gain: 1000
Bandwidth: 20 Hz - 450 Hz
Noise: < 5 µV
Input Impedance: > 10,000,000 M Ohms
Supply voltage: +4.5 Vdc
CMRR @60 Hz (dB): > 96dB (typically 110dB)
Cable: Highly flexible grade, length 1.25 m (custom lengths on request)
Plug: Direct connection to DataLINK or DataLOG
Mass: 12 g (excluding cable and connector)
Electrostatic Discharge Circuit protected

Surface EMG Amplifier
(Part # SX230FW) Specifications

Two 4mm snap connectors on 100mm wires: use with reusable or disposable SEMG electrodes with 4mm snap
Gain: standard unit 1000 (100 also available)
Bandwidth: 20 Hz - 460 Hz
Noise: < 5 µV
Input Impedance: > 10,000,000 M Ohms
Supply Voltage: +4.0 to +5.0 Vdc
CMRR @ 60 Hz (dB): > 96 dB (typically 110dB)
Cable: highly flexible grade, length 1.25 m (custom lengths on request)
Plug: direct connection to DataLOG , DataLINK or K800
Mass: 12 g (excluding cable & plug)
Electrostatic Discharge Circuit protected

Ground Reference
(Part # R306) Specifications

Type: Reusable
Cable: Highly flexible grade, length 1.25 m
Application: Connection to disposable electrodes using a 2mm spring plug

Ground Reference
(Part # R506) Specifications

Type: Reusable
Cable: Highly flexible grade, length 2.0 m
Application: Connection to reusable or disposable SEMG electrodes with 4mm snap

Application Tape
(Part # T350) Specifications

Double sided medical grade Die cut for ease of application (350 pieces per pack)

Surface EMG Electrodes
(Part # SEN3001) Specifications

Single patient/subject use. Multiple reapplications. (20 packs of 6 electrodes)

Active EMG Sensor Specifications

The above diagram illustrates the main components of the Biometrics active EMG sensor. This sensor has the following benefits:

  • Differential electrodes to detect low level signals in a noisy environment.
  • Very high input impedance (>10,000,000 M Ohms) to minimise the differential pickup due to mismatches in skin contact resistance. With other commercially available systems the significantly lower value of input impedance makes the skin preparation critical and the quality of signal is reduced in dynamic applications.
  • A high-pass filter to remove DC offsets due to membrane potentials. The Biometrics sensor includes a third order filter (18bB / octave).
  • A low-pass filter to remove the unwanted frequencies above about 450Hz. It is very important to remove these high frequencies when interfacing to a computer that is sampling the signal since they would be converted to a lower frequency and mixed with the original signal.
  • The SX230 includes an eighth order elliptic filter (-60bB at 550Hz).
  • A low noise instrumentation-amplifier front-end with a common-mode rejection ratio of typically 110 dB.

Additional Information

Taking EMG Measurements
Display and Analysis of EMG Data
Hints for Analyzing EMG

DataLINK and DataLOG are trademarks of Biometrics Ltd.