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.

The SX230F sensor has 2 flying leads for 2 disposable electrodes using a standard button catch. The length of each flying lead is 4 inches. Either the R206 or R306 ground earthing cable can be used. All other specs are identical to the SX230.

The cable R206 comes complete with a convenient elasticised wristband for ease of use. The cable R306 comes with a standard 2 mm spring plug for connection to proprietary disposable electrodes with a 2 mm spring socket.

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

Ground Reference
(Part # R206) Specifications

Type: Reusable
Cable: Highly flexible grade, length 1.25 m
Application: Wrist strap or user preference

Application Tape
(Part # T350) Specifications

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

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

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.