RU2701197C1 - Method for hybrid recording of human cerebral metabolic activity - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to methods of measuring metabolic activity in various areas of human brain. Method for hybrid detection of human cerebral metabolic activity comprises co-location on human skin of proximity infrared spectroscopy sensors, detecting concentration of oxyhaemoglobin HbO and deoxyhemoglobin HbD in cerebral blood flow and located on scalp in points where there is no hair coat, and electrodes detecting cerebral electrical activity, wherein near infrared spectroscopy sensors are placed at points of the international electrodes arrangement system "10-20", where there is no hair coat.

EFFECT: technical result consists in improvement of accuracy of recorded signals of human cerebral activity by reducing distortions and supplement electroencephalographic data with near infrared spectroscopy data.

1 cl, 2 dwg

Description

The invention relates to medicine, namely to methods for measuring metabolic activity in various areas of the human brain.

Registration methods measuring the electrical activity of the brain are known in the art. Such methods use a set of electrodes whose contact surface is made of metal — typically AgCl or AuCl — to increase conductivity. The result of registration is an electroencephalogram reflecting metabolic activity in the form of an instantaneous voltage value during the time of registration.

The disadvantage of these methods is the low accuracy of signal registration, expressed in low spatial resolution of the order of 1 cm and a high error rate. Errors arise due to distortions caused by electrical signals from the muscles of the human head, electromagnetic interference.

An electroencephalograph protected by USSR patent N 880241, class. АВВ 5/04 (application of Germany N 2727583 dated 06/20/77), using a registration method in which electrodes with a metal contacting surface are used.

The disadvantages of the registration method that uses the electroencephalograph are the same as the previous wide group of similar registration methods.

The problem to which the claimed invention is directed is to provide high accuracy in recording metabolic activity of the human brain.

The problem is achieved through the use of a hybrid registration method for the metabolic activity of the human brain, which consists in the joint use of: 1) electrodes for recording an electroencephalogram; 2) near infrared spectroscopy sensors that measure the levels of oxyhemoglobin HbO and deoxyhemoglobin HbD in the cerebral blood flow.

The possibility of using near infrared spectroscopy sensors to record the metabolic activity of the brain is determined by the fact that all biological tissues to varying degrees transmit electromagnetic radiation of various frequencies and intensities. From the point of view of spectroscopy, this is because various molecules selectively absorb electromagnetic radiation of various lengths. Similarly, tissues also reflect electromagnetic radiation to varying degrees. Near infrared light can penetrate several centimeters into biological tissues, which allows a non-invasive examination of the human brain.

In the process of spectroscopic registration, photons from the light source are directed along a certain path through the tissue under investigation back to the detector located at a small distance from the source (Fig. 1). Despite the significant attenuation of light waves due to absorption and scattering processes, nevertheless, the spectroscopic features of the molecules through which they passed on the way to the detector are preserved in the detected radiation.

The spatial resolution of the near infrared spectroscopy sensors is about 30 mm, while the signals are recorded with a low error rate, which exceeds the quality of registration of electroencephalographic technology. At the same time, infrared sensors cannot be placed in the area of the scalp of a person’s head, since the hair introduces significant distortions into the signal recorded by infrared sensors. Therefore, infrared sensors are located only in the forehead of the human head, where there is no hairline according to the international positioning system of electrodes 10-20 at the points of application F7, Fp1, G, Fp2 and F8 (Fig. 1). At all other points of application (Fig. 1), according to the system 10-20, electrodes can be placed with a metal contacting surface that record the electroencephalographic activity of the human brain.

Through the use of electroencephalographic electrodes, together with the sensors of near infrared spectroscopy, the quality of the entire recording system as a whole is improved. Near infrared spectroscopy sensors complement the data recorded by electroencephalographic electrodes.

The technical result achieved is to increase the accuracy of the recorded signals of human brain activity by reducing distortion and supplementing electroencephalographic data with near infrared spectroscopy data.

The invention is illustrated by figures that do not cover and, moreover, do not limit the entire scope of the claims of this technical solution, but are only illustrative materials of a particular case of execution.

In FIG. 1 placement of near infrared spectroscopy sensors at application points F7, Fp1, G, Fp2 and F8 according to the international positioning system 10-20.

In FIG. 2 is a conventional image of the passage of photons through the test tissue from the light source to the detector.

Claims (2)

 1. A method for hybrid registration of metabolic activity of the human brain, comprising co-placing on the human scalp sensors of near infrared spectroscopy, recording the level of concentration of oxyhemoglobin HbO and deoxyhemoglobin HbD in the cerebral blood flow and located on the scalp at points where there is no hairline, and electrodes, registering the electrical activity of the brain, characterized in that the sensors of near infrared spectroscopy are placed at points in international systems Accommodation "10-20" electrodes, where there is no hair growth. 2. The method according to p. 1, characterized in that the sensors of near infrared spectroscopy are placed at points F7, Fp1, G, Fp2 and F8 of the international electrode placement system "10-20".

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