Sensors for the MR environment

Sensors for peripheral signal recordings in the MR environment

Measuring peripheral physiological signals during fMRI can add valuable information about physiological processes to your studies. For example, measures of arousal or muscle movements could provide complementary data to the EEG and/or fMRI data. Our range of MR sensors allow you to easily add such measures to your research when used in combination with the BrainAmp ExG MR.

3D Acceleration Sensor MR

The 3D Accelaration Sensor MR consists of the sensor (2 sensors with cables of different lengths are supplied) and a pre-amplifier. It captures movements in three dimensions and its primary application is to detect and record movement/acceleration of the extremities.

For a non-MR-usable version of this sensor click here.

GSR MR Sensor

The GSR MR Sensor measures skin conductance (SC) – a parameter for emotional and cognitive states, stress and pain. It uses the exosomatic recording principle with direct current (DC). This means that a constant voltage of 0.5 V is applied in order to acquire the skin conductance. The sensor consists of 2 surface electrodes and a GSR module, that converts the electric SC to a voltage recorded by a bipolar amplifier input. A GSR-specific gel (Edalyt) is also suplied.

For a non-MR-usable version of this sensor click here.

Respiration Belt MR

The Respiration Belt MR consists of an elastic belt with a pouch, a pneumatic sensor, a transducer and a cable for the connection to the amplifiers’ auxiliary ports. It measures the thoracic or abdominal respiratory movements and converts them into electrical voltage.

For a non-MR-usable version of this sensor click here.

NOTE: Respiration plays an extremely critical role in the MR environment, as it may not only be a confounding factor, but also a source of related artifacts. It can be linked to movement artifacts, physiological alterations, induced field inhomogeneity, or interference with the experimental paradigm. Therefore respiratory effects cannot be ignored (see e.g. Thomason et al. 2005).

Multitrode MR electrodes for surface EMG

For bipolar surface EMG measurements multitrode MR electrodes should be used. They have some special features that make them suitable for use in the MR environment: they have a current-limiting resistor, they are an incomplete ring to avoid induced eddy currents, and are bundled in a spiral tube so that the lead wire cannot come into direct contact with the participant.