With the eeg in the boot record to the surface of the skin "the waveform of brain electrical activity map"
Human tissue cells is always in constant spontaneously produce a weak electrical activity.Using electrodes placed on the scalp to the brain's electrical activity of derivation and enlarged by electroencephalograph recorded on special paper, namely, it is concluded that a waveform, amplitude, frequency and phase of the graphics, curve, is the electroencephalogram (eeg).When brain tissue pathology or functional change, the curve of the corresponding change, thus provide the basis for clinical diagnosis and treatment.
By CT scanning, axial CT scan is the electronic computer English abbreviations.Its basic principle is to use the head for "X-ray" absorption rate of different imaging.The bones in the skull, brain tissue and cerebrospinal fluid density is not phase of the organization With, the X-ray absorption is not consistent.According to the difference of a X wiring harness from multiple directions, the faults along the head of a selected level to illuminate, measured through the amount of X-ray, digital, calculated through the layers of surface groups each unit volume absorption coefficient, and then a imaging reconstruction image.
Rotating body feel as dizziness, head heaviness ask dizziness.Shall be by a neurologist or ent doctor decided to do what kind of auxiliary examination.
Eeg machine maintenance matters needing attention
Eeg machine storage and use of the site should be dry, clean, temperature not too high or too low, the floor to prevent vibration, prevent the dust into the instrument.In when not in use should be a cloth cap.The eeg must have the specialist is responsible for the warehousing and use.In addition, still should pay attention to the following matters.
(1), the eeg machine if stop using for a long time, should be electricity, on a regular basis to ward off the moisture and prevent rust, general electricity once or twice a month, every time electrify time an hour or so.
(2), the eeg machine use the ink is dedicated, should not be written in other ink, in case the stylus jams.If discover to there is leakage phenomenon, the ink tank should immediately stop using, handle in time.Pay special attention to not let the ink into the recorder, because of adverse effects on the performance of the recorder.
(3), should pay attention to protect the recording pen, in order to obtain high frequency response, stylus is always made of lightweight, but also cause the strength of the pen is not enough, easy to damage.When use to prevent overload signals to the recorder.
(4) to try to get the baseline, record is in middle position, such as fault found makes stylus slant to the side, should be
In a timely manner to turn off the guide records switch, because the pen recorder when partial to the coil current biggest, in the long run will coil overheating or even damage.
(5), be careful not to let the salt water wet electrode wire, line, instrument panel, etc., if the salt water intrusion in, can reduce insulation ac interference caused by disease.
6, often should monitor the chlorination of the electrodes, and in the use of a chloride processing after a period of time.
Basic knowledge of electroencephalogram (eeg)
Cranial nerve cell is spontaneous, rhythmic put telephone, known as brain waves of electrical activity in the continuous.Cell electric tracing is applied the technology of electronic amplification amplify the electrical activity of brain of 1 million times, the potential difference between two points on the scalp, or has nothing to do with scalp electrodes or special electrode potential difference between the EEG, EEG line, called clinical EEG (electroencephalogram, EEG) fixation, to study brain function.Eeg is because the space of the eeg features as a longitudinal axis, with time features as horizontal uranium and show out.Structure into several basic features of brain wave frequency, amplitude, waveform, phase, and amplitude modulation, brain waves appear in the form of adjustment and distribution, etc., which is the basis of clinical eeg analysis.
(1) the frequency
1 - a wave from baseline to it returned to baseline the time required to call cycle, namely the bees to wave, or trough to trough time units in milliseconds (ms).
(2) a number of weeks per second is called frequency, in Hz than said.(3) more than 10 mu v wave in the percentage accounted for the last 1 minute said index, such as alpha rhythm within 1 minute accounted for 15 seconds, the index of 15/60, or 25%.
(2) the amplitude
A wave by wave amplitude, the distance to the baseline in microvolt (mu v) said.Electroencephalogram (eeg) often moved to occipital eeg, come out of those basic rhythms of wave height for the standard, such as < 25 mu v said low wave amplitude, 25 to 50 mu (or is) v for the amplitude, 50-100 mu v (or 75) to high amplitude, more than 150 mu v for high volatility.Normal adult occipital amplitude is higher than the forehead. Bilateral symmetry, there are a few advantages of lateral amplitude is lower than the dominant side, but not more than 30%.
(3) the waveform
Brain waves can because of its frequency, amplitude and potential changes and form various waveform, such as sine or class sine wave, half arc shape wave, sawtooth wave, bimodal wave, spike wave, sharp wave, tip is slow.
(4) phase
A wave generated by the deflection of the vertical can phase.(1) single phase are: turn to the baseline case.All landowners duplex wave: first turn to the baseline case and then to the other all deflection.(3) the polyphase wave: a wave from the baseline repeatedly to the deflection many times on both sides.(4) upward deflection for negative phase wave, the downward deflection of positive phase wave.5. Two trace of lead, the amplitude difference between the time relationship can produce a.Such as lead two amplitude by baseline upward or downward deflection at the same time, the phase difference of 0 degrees said with phase.Vice generates a 90 - degree differs for
Different phase.Such as two lead wave at the same time to the baseline in the opposite direction of the deflection and the difference is equal to 180 degrees, it is called a phase inversion, it can serve as an indication of the positioning of brain disease.
(5) and amplitude modulation adjustment
(1) to adjust: refers to the brain waves of basic frequency of regularity and stability, in the same part of the basic frequency is stable, and the difference should not be more than 1 times/SEC, such as more than 2 times/SEC regulation shall be deemed to be poor;On the left and right hemispheres symmetrical parts the same time should not be more than 0.5 times per second, to adjust the difference more than 1 times/SEC.
(2) the amplitude modulation: refers to the brain by basic led string of amplitude change regularity, normally in the form of fusiform, and amplitude
