sEMG sensors
Size
the size of the electrodes in the direction of the muscle fibers is max. 10mm.
Inter electrode distance
(for sensors restrict to bipolar sensors only) ‘Inter electrode distance’ defined as the centre to centre distance between the conductive area’s of 2 bipolar electrodes. 20 mm. / not exceed 1/4 of the muscle fibre length(for relatively small muscles; In this way unstable recordings, due to tendon and motor endplate effects can be avoided.)
Sensor construction
(defined as: the (mechanical) construction which is used to integrate the electrodes, the cables and (if applicable) the pre-amplifier.) a construction with fixed inter electrode distance, built from light weight material. Cables need to be fixed using (double sided) tape or elastic band in such a manner that pulling artefacts can be avoided. If in fast dynamic contractions the sensor construction causes too much (movement) artefacts (due to inertia of the construction), SENIAM recommends to fix the inter electrode distance using (double sided) tape or rings.
信号采集
Skin preparation
1️⃣ shave the patient 2️⃣ clean the skin with alcohol and allow the alcohol to vaporise
Positioning the patient in starting posture
the posture of the patient (sitting, lying, prone, etc…) as well as the position and orientation of the body segment at which the electrode will be placed.
Determination of sensor location
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With respect to the longitudinal location of the sensor on the muscle SENIAM recommends to place the sensor halfway the (most) distal motor endplate zone and the distal tendon.
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With respect to the transversal location of the sensor on the muscle SENIAM recommends to place the sensor at the surface away from the ‘edge’ with other subdivisions or muscles so that the geometrical distance of the muscle to these subdivisions and other muscles is maximised.
Soleus比目鱼肌
Tibialis anterior胫前肌
Support the leg just above the ankle joint with the ankle joint in dorsiflexion and the foot in inversion without extension of the great toe.
Placement and fixation
Inter electrode distance
Orientation of electrodes
‘Electrode orientation’ is defined as the position of the line between the 2 bipolar electrodes with respect to the direction of the muscle fibres. SENIAM recommends that the bipolar SEMG electrodes should be placed around the recommended sensor location with the orientation parallel to the muscle fibres.
Fixation on the skin
SENIAM recommends to use elastic band or (double sided) tape / rings for the fixation of the electrodes(construction) and cables to the skin in such a way that the electrodes are properly fixed to the skin, movement is not hindered and cables are not pulling the electrodes(construction).
Location of the reference electrode
Depending on the application SENIAM recommends to use the wrist, the proc. spin. of C7 or the ankle as the standard location of the reference electrode.
Testing of the connection
The clinical tests which are described are generally accepted muscle tests which guarantee (under normal circumstances) activity of the tested muscle. The clinical test has to be started from the starting posture described in the SENIAM recommendations for sensor locations and has to be performed according to the recommendations. The clinical tests described are not ‘selective’ contractions in which only the desired muscle is active and all other muscles are inactive.