METHOD AND APPARATUS FOR SCALP ELECTRIC POTENTIAL MEASUREMENT Russian patent published in 2013 - IPC A61B5/476 A61B5/478 G01R19/00 

FIELD: medicine.

SUBSTANCE: group of inventions refers to medicine and medical equipment, particularly to methods and apparatuses for scalp electric potential measurement. The apparatus comprises a number of sensors obtaining the initial measurement of a scalp electric potential through a hair-covering and an air contact area; a number of preamplifiers connected to one of the appropriate mentioned sensors. The contact area produces a high and variable coupling impedance of the source and the scalp. Each preamplifier contains a broadband high-impedance input and an active bias circuit generating input impedance more than 10 petaOhm over the range from 0.01 Hz to 400 Hz; a high-gain low-noise operating amplifier with the input impedance of 10 teraOhm; and a shielded feedback and bias circuit. The preamplifier is configured to have the input impedance substantially higher than the impedance produced by the source-sensor contact area. One version of the implementation of the method for scalp electric potential measurement, the preamplifier obtains the initial measurement of the scalp electric potential and forms a pre-intensified measurement of the scalp electric potential. The measurement is taken through the hair-covering and air. In the other version of the implementation of the method, an input signal of the initial scalp electric potential is obtained from the number of sensors to generate an appropriate number of channels. It is followed by the signal pre-amplification by the preamplifier with the high input impedance to form the pre-intensified measurement of the scalp electric potential. Then, a measurement mode is configured in a group containing a channel mode relative to a reference channel, a channel mode relative to a middle channel and a differential interchannel mode. Then, the pre-intensified measurement of the scalp electric potential is biased with maintaining the mentioned high input impedance; a channel gain is adjusted to differential obtaining of the channel signal. An additional stage providing the processed channel signal is suppressing radiofrequency interferences of the channel signal with maintaining adjustment of the gain and the phase; a common-mode of the channel signal is suppressed, and the band-pass channel filtration is provided. The processed channel signal is digitised to present a digital signal of the measurement of the scalp electric potential, characterising the mentioned input signal measured according to the mentioned chosen measurement mode.

EFFECT: use of the group of inventions allows more effective measurements of the scalp electric potential due to the preamplifiers, and allows reducing the need of exfoliating of the necrotic epithelial cells or application of abrasive or conducting gels.

27 cl, 11 dwg