JP3418730B2 - Venous olfactometer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a venous olfactory test apparatus for objectively evaluating a human olfactory sense. [0002] A venous olfactory test is a clinical test widely used for diagnosis of olfactory disorders. In this test, for example, a vitamin is intravenously injected into a subject's arm and nasal breathing is slowly performed. The vitamins evaporate in the lungs and pass through the nasal passages,
The subject senses the smell. Subjects declare and record the time when they began to smell and when they no longer smell.
Because the latency and duration are determined by the subject's response,
If the subject gives a false answer, it will be difficult to measure. As a method for electrophysiologically evaluating the sense of smell of a human, it is common to average the changes in brain waves when the odor is inhaled, but it is necessary to give the odor in a pulse form. For this reason, it was impossible to evaluate the venous olfaction, which generates a persistent odor stimulus and cannot be made into a pulsed stimulus, electrophysiologically, that is, objectively. [0004] Accordingly, an object of the present invention, which has been made in view of the above points, is to provide an objective venous olfactory test apparatus which overcomes the above-mentioned drawbacks. [0005] The invention of an objective venous olfactory test apparatus according to the first aspect of the present invention, which achieves the above object, comprises a means for measuring the time of intravenous injection of venous olfactory to a subject. An electrode attached to the forehead of the subject, for receiving the subject's brain waves, means for amplifying the brain waves received by the electrodes, a filter for extracting the amplified brain waves of 30 Hz or more, and processing by the filter Recording means for recording the brain waves obtained together with the time of intravenous injection of venous olfactory to the subject. [0006] When smell is felt, a so-called γ-wave or an induced wave, a high-frequency brain wave of 30 Hz or more , is generated from the sense of smell in the human frontal region. This has been confirmed by experiments.
The subjects were volunteers with normal olfaction and patients complaining of olfactory disturbance, with explanation and consent. One ampoule of alinamin was intravenously injected in 20 seconds as usual while an electrode was attached to the forehead and the brain wave was recorded on a tape or a hard disk of a personal computer. There was a burst-like increase in electroencephalographic amplitude consistent with the expression of the alinamine odor from the frontal region. This increase is 30H
It was remarkable at a frequency of z or more, and was about 5 μV to 20 μV. Approximately 70% of those who could recognize the alinamin odor could be detected. It is known that high frequency brain waves are emitted from the olfactory bulb when odor is stimulated in both animals and humans, and the olfactory bulb is suspected as a source of this phenomenon. However, the possibility of orbital frontal cortex cannot be ruled out. If the frontal sinuses are below the electrodes, it is difficult to obtain intracranial potentials, but considering that extremely clear development of the frontal sinuses could record the clearest response, at least the source was the cranial sinus. And the contamination of EMG is considered negative. As described above, the source of the electroencephalogram is not clear, but is known to be generated by venous olfaction. Therefore, if this brain wave is detected on the scalp of the frontal region, it is possible to objectively evaluate the expression of venous olfaction. According to a second aspect of the present invention, the objective venous olfaction test apparatus further comprises means for detecting a subjective response to the odor of the subject, wherein the recording means simultaneously records the subjective response of the subject. It is characterized by doing. In this way, a comparison with a conventional venous olfactory test can be made. FIG. 1 is a diagram showing the configuration of an objective venous olfaction test apparatus according to the present invention. The electrodes 1, 2 and 3 are mounted on the forehead of the subject 10. Electrodes 1 and 3 are connected to the input of amplifier 4 and electrode 2 is grounded. The brain waves obtained by the electrodes 1 and 3 are amplified by the amplifier 4 and supplied to the recorder 6 through the high-pass filter 5 that passes only the brain waves having a frequency of 30 Hz or more . This filter may be a band-pass filter that passes only brain waves having a frequency of 30 Hz to 200 Hz, for example.
The recorder 6 records the supplied brain waves. Further, a rectifier circuit and an integrating circuit may be arranged between the high-pass filter 5 and the recorder 6 to add a function of recording the brain wave amplitude on the recorder 6. The recorder 6 is also supplied with signals from an intravenous injection execution detection switch 7 of a syringe 8 and a subject response switch 9. When venous olfactory is injected intravenously with the syringe 8 while recording the brain waves induced from the electrodes 1, 2 and 3 with the recorder 6, the signal from the intravenous injection detection switch 7 is recorded by the recorder 6. . This signal may be generated continuously during the injection, or one or both of the start and end may be recorded.
May be used as a trigger to start recording. After this injection, if the subject 10 feels a smell, when the subject responds by pressing the subject response switch 9, the timing at which the smell is felt is recorded. The recorder 6 only needs to be capable of displaying a change in data in a time series as a recording graph. The recorder 6 may be in an analog format or may be displayed on a computer via an AD converter and displayed. The format does not matter.
Also in the high-pass filter 5, a signal may be digitized by placing an anti-aliasing filter and an AD converter immediately after the amplifier 6, and processed by a digital filter. Further, the syringe 8 may be automatically injected by a syringe pump instead of manually injected by the examiner. In such a case, the on / off timing of the syringe pump is recorded instead of the intravenous injection detection switch 7. If the operation of the syringe pump itself is controlled by using a computer as the recorder, the on / off timing of the syringe pump can be obtained without the intravenous injection enforcement detection switch 7,
The intravenous injection execution detection switch 7 can be omitted. The injection time of the venous olfactory, the subjective response of the venous olfactory perception of the subject, and the change of the electroencephalogram are plotted as graphs, and the examiner can objectively evaluate the venous olfaction of the subject. FIG. 2 is a graph showing an example of a measurement result actually measured by the apparatus shown in FIG. For reference, in addition to the respiration curve and the frontal region, the brain waves from the right and left temporal regions are also displayed in addition to the brain waves of the frontal region. The vertical axis is one large scale
The intravenous olfactory is injected intravenously in 20 seconds from 0 μV and the horizontal axis is 0. The subjective response by the subject response switch is
When the test subject felt the smell, when pressed, it was displayed upward in the graph. Although the subjective response by the subject response switch is from 25 seconds to 70 seconds, it can be seen that a burst-like brain wave is emitted from the frontal region in accordance with this. According to the present invention, the examiner can know the expression of the venous olfaction of the subject by the electroencephalogram even if the subject does not report the expression of the venous olfaction to the examiner. It can be carried out.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a configuration of an objective venous olfaction test apparatus according to the present invention. FIG. 2 is a graph showing an example of a measurement result measured by the objective venous olfactory test device of FIG. 1; [Description of Signs] 1, 2, 3 Electrodes 4 Amplifier 5 High Pass Filter 6 Recorder 7 Intravenous Injection Enforcement Detection Switch 8 Syringe 9 Subject Response Switch 10 Subject

Claims (1)

(57) [Claim 1] Means for measuring the time of intravenous injection of venous olfactory to a subject, an electrode attached to the forehead of the subject and receiving brain waves of the subject, Means for amplifying the electroencephalogram received by the electrode, and 30H of the amplified electroencephalogram
A venous olfaction test apparatus, comprising: a filter for extracting z or more; and recording means for recording the brain waves processed by the filter together with the time at which the subject is injected with venous olfactory intravenously.