JP4399626B2 - Sensory stimulator - Google Patents

Description

The present invention relates to a sensory stimulation device, and more particularly, is suitably applied to a case that stimulate human sensory nerve tissue.

  Conventionally, a sensory stimulation method for stimulating a sensory nerve tissue of a living body basically stimulates a pseudo tactile sensation by indirectly applying mechanical stimulation such as pressurization or vibration to a hand. For this reason, there are problems in mechanical resolution and accuracy, and further problems such as an increase in the size of the apparatus.

  On the other hand, in the medical field, an invasive technique for directly performing electrical stimulation on nerve tissue in the brain has been practiced for a long time, mainly for the purpose of research such as higher cranial nerve activity and treatment of Parkinson's syndrome. Although this method can directly stimulate the sensation as compared with the above-described mechanical type, it is necessary to make a direct contact with a target tissue by performing a craniotomy or inserting an electrode into the brain. Moreover, it is not considered that this method is generally used for sensory stimulation such as information equipment.

  In recent years, transcranial magnetic stimulation (Transcranial Magnetic Stimulation) has begun to be used as a non-invasive technique for nerve stimulation of the brain or the like (hereinafter, the stimulation method is referred to as TMS).

  TMS is a technique for stimulating the central nervous system of a human body from an 8-shaped coil provided outside the skull. In this method, since the skull has high electrical resistance, it cannot be stimulated by applying an electric current to the inner brain from the outside of the skull. Therefore, a magnetic field that is not attenuated by the skull is used. In this case, when a fluctuating magnetic field is generated in the coil by applying a pulsed large current to an 8-shaped coil provided on the scalp, the magnetic field reaches the brain tissue below the skull without being attenuated. An eddy current is generated around the fluctuating magnetic field inside the human body, and the brain is electrically stimulated by the eddy current (see, for example, Non-Patent Documents 1 to 6).

The feature of TMS is that it can stimulate the brain non-invasively as described above. In particular, since TMP can be measured in units of milliseconds to generate pulsed stimulation, this TMS and MRI (Magnetic Resonance Imaging) When combined with diagnostic imaging technology with excellent spatial resolution, such as PET (Positron Emission Computed Tomography), it is possible to infer which part of the human brain is working at what timing from the reaction by the stimulus. For this reason, in addition to the research field, it has recently been put to practical use in the evaluation of pyramidal lesions and the identification of the lesion site.
Barker AJ, Jalinous R, Freeston IL: Noninvasive stimulation of human motor cortex. Lancet ii: 1106-1107, 1985. Post RM, Kimbrell TA, McCann UD, Dunn RT, Osuch EA, Speer AM, Weiss SRB: Repetitive transcranial magnetic stimulation as a neuropsychiatric tool: Present status and future potential.J ECT 15; 39-59,1999. Wassermann EM: Risk and safety of repetitive magnetic stimulation: report and suggested guidelines from the international workshop on the safety of repetitive transcranial magnetic stimulation, June 5-7, 1996. Electroenceph clin Neurophysiol 108: 1-16, 1998. Chen R, Gerloff C, Classen J, Wassermann EM, Hallett M, Cohen LG: Safety of different inter-train intervals for repetitive transcranial magnetic stimulation and recommendations for safe range of stimulation parameters. Electroenceph clin Neurophysiol 105: 415-421, 1997. Satoshi Kimura, Yukio Mano, Yoshikazu Ukawa, Ryu Rin, Motohiro Kato, Hiroshi Kawamura, Tetsuya Tamaki, Sadatoshi Tsuji, Takashi Tsubokawa, Masafumi Machida: Standard methods of magnetic stimulation. EEG and EMG 22: 218-219, 1994. Satoshi Kimura, Yukio Mano, Yoshikazu Ukawa, Siryu Rin, Motohiro Kato, Tetsuya Tamaki, Sadatoshi Sakaki, Masafumi Machida: Recommendations on “Safety and Clinical Application of Transcranial High Frequency Magnetic Stimulation”. EEG and EMG 27: 306, 1999.

  By the way, in such TMS, since the figure-shaped coil must be accurately fixed around the head of the human body to be a subject, the operation is complicated, and a fluctuating magnetic field is used to generate an electrical pulse of nerve. For this reason, it is inevitable to connect the large current generating means to the 8-shaped coil, so that not only the apparatus becomes large but also there is a restriction such as restraining the subject to the apparatus. In addition, in this TMS, the fluctuation magnetic field has the advantage that it can reach the brain without being affected by tissues such as bones, but on the other hand, since it is a technique of puncture by eddy current from a coil or fluctuation magnetic field, it is a shallow tissue such as skin or subcutaneous tissue It is not suitable for stimulation of nerves scattered around.

  In particular, the sensory nerve terminal tissue is suitable for causing a physically strong electrical stimulation by eddy currents forcibly even from the middle of the nerve as in TMS. Therefore, when it is relatively shallow like a certain sensory receptor, it cannot be stimulated locally. Furthermore, there is a problem that it is impossible to reduce the size to a minute level because the figure-shaped coil itself becomes a restriction.

  Furthermore, in TMS, a very strong current is forcedly generated in the body to ignite the nerve, so that stimulation for vision and hearing is possible. However, if the purpose is to stimulate the sense, It is sufficient if it is a stimulus for the terminal end, and forcibly stimulating nerves with eddy currents in the middle will cause a sensation, but it is not efficient, and sufficient information such as video and music cannot be given. This means that the stimulation is given in parallel to the set, not individual nerves. When stimulation is applied to individual nerves in parallel, the permeability of the varying magnetic field in the body is reduced. On the contrary, the advantage of high becomes a restriction, and the resolution of the stimulus is reduced.

  As described above, in TMS, since the figure 8 coil must be accurately fixed around the head of the human body to be the subject, the operation becomes complicated and the large current to the figure 8 coil restrains the subject. Since it is unavoidable to connect the generating means, not only the power consumption is increased, but the device itself is large-scale, and the sensory nerve endings such as the sensory nerve ending tissues that do not go through the bones generate sensations. Various problems, such as the fact that stimulating in parallel to a set of individual nerves rather than individual nerves, is constrained by the advantage of high permeability of the varying magnetic field in the body, reducing the resolution of the stimulus was there.

  If even one of these problems can be solved, the sense can be stimulated easily, and it is considered to be a highly useful technique that can be applied in various fields. If this method is applied to the virtual reality field, it is considered that the reality can be enhanced.

The present invention has been made in view of the above, it is intended to propose a resulting Ru sense sensory stimulator enhance usability.

This onset bright order to solve such problems, is an electric field source, an electrode is close in a non-contact to the living body, among the plurality of frequencies allocated to sense to cause the living body, a signal of specified frequency Selection means for selecting, and an electric field applying means for applying a signal selected by the selection means to the electrode and applying a quasi-electrostatic field having a strength larger than that of the radiation electric field and the induction electromagnetic field to the sensory nerve terminal in the living body And have.

  According to the present invention, an electric field for generating a predetermined sensation in the living body is applied to the sensory nerve tissue terminal, thereby applying a frequency at which the superficial sensory nerve tissue terminal resonates. Therefore, it is possible to present a sense more efficiently than the magnetic field, and thus the usefulness can be increased.

  Further, according to the present invention, by applying a quasi-electrostatic field to the sensory nerve tissue terminal as an electric field for generating a predetermined sense in the living body, an extremely small current is applied to the sensory nerve tissue terminal, In addition, since an electric field can be applied to the sensory nerve tissue end without requiring a coil for generating a magnetic field, low power consumption and miniaturization can be realized, and thus usefulness can be increased.

  The present invention will be described in detail below with reference to the drawings.

  The present invention suggests that the human body is an electrostatic conductor, and that the terminal of sensory nerve tissue in the living body has a specific electric field sensitivity, as suggested by empirical facts that we experience static electricity everyday. By utilizing the fact that the quasi-electrostatic field has high resolution with respect to the distance, a quasi-electrostatic field having a frequency corresponding to the sensory nerve tissue or a frequency and waveform corresponding to the sensory nerve tissue is applied. It is a non-contact and non-invasive method for stimulating and presenting sensations such as touch and temperature.

(1) Sensory nerves and quasi-electrostatic field The present applicant has discovered that quasi-electrostatic fields produce various sensations such as warm and tactile sensations. What is important in this discovery is not a simple electrostatic field, but a quasi-electrostatic field, that is, a fluctuating electric field. We find that the generated sensation differs depending on the frequency, and it depends on different signals such as how the frequency and waveform rise. It is thought that the sensory nerve tissue terminal reacted.

  The electrochemical mechanism at the sensory nerve tissue terminal is not fully understood except for visual, auditory, and painful sensations, but there is a key to the sensory receptor (receptor) called the Rolentini bottle Conceivable. This Lorentini bottle is a sensory receptor scattered on the head of a shark, for example, a bottle-like organ with gelatinous inclusions. This organ detects the electric field generated by the living organism serving as food, and sand. Used to prey on flounder and the like lurking inside. At the same time, it has been found that Lorentini bottles have the function of sensing seawater temperature. From this, as an electrochemical mechanism in which the Rolentini bottle reacts, a Lorenti functional protein (an electrochemical property similar to a piezoelectric body) is considered. That is, electrostriction occurs within the substance with respect to the electric field, and at least a part of the inclusion polymer rapidly deforms with respect to the temperature, so that a change in the potential of the substance induces nerve firing. It is considered that a minute molecular level reaction close to piezoelectric occurs in the Lorentini bottle.

  Similarly to the fact that the tail of the living body is left as the sacrum of the human body through the process of evolution, it is thought that what controls the function of the Lorentini bottle is at the end of the sensory nerve tissue that appears in the human body. It is considered that pressure sensation such as tactile sensation or warm sensation is presented as a “sensation” of the human body due to electrochemical properties similar to the piezoelectric body at the end. Furthermore, it is well known that a sense that does not actually exist is felt, and when the applicant holds his hand over a quasi-electrostatic field generated from an electric field generation source, a warm sensation that is not actually present is presented. The experimental results are obtained.

(1-1) Sensory Nerve (1-1-1) Sensory Conduction Path Here, regarding the temperature sensation of the skin of the extremities and trunks, the transmission path and the physical division of sensory receptors at the sensory nerve tissue terminal are detailed. explain.

  The thermal sensation and the tactile sensation that is coarser than the thermal sensation pass through the spinothalamic system (also called the spinal lemniscus). As a pathway for transmission of warm pain to the spinal cord and brain, the sensory neuron (second neuron) axon in the dorsal horn passes through the white (front) commissure and the anterior lateral cord (frontal cord) on the opposite side And the lateral cord) ascending as the lateral spinal thalamic tract, ending in the posterior lateral ventral nucleus (VPL) of the thalamus. Next, the axons of the VPL nucleus neurons (tertiary neurons) in the brain thalamus end up in the primary somatosensory cortex of the cerebral cortex (center retroversion; 3-1-2 areas of Broadman). And by projecting on the somatosensory area of the cerebral cortex, it will be recognized as a sensation for the first time. This spinal thalamic tract system has a nature of transmitting primitive and basic life sensations, and it is known that emotional elements (pleasure and discomfort) are associated with these sensations.

(1-1-2) Classification of sensory receptors On the other hand, sensory receptors as terminals can be classified into the following four types according to stimulus specificity.
a) chemoreceptors: olfaction (olfactory cells), taste (miso).
b) Mechanoreceptors: proper perception (muscle spindles, Golgi tendon organs), tactile sensation (Meissner body, Pharter pachini body, etc.), vestibular sensation (hairy cells of the vast part of the semicircular canal and equilibrium plaques) ), Hearing (cortisian hair cells), pain (free nerve endings).
c) Thermoreceptors: warm sensation (Ruffini body), cold sensation (Clauze termination), free nerve endings.
d) Photoreceptors: vision (retina rods and cones).

  Among these, the mechanism relating to the temperature receptor and the mechanoreceptor of c) has not been sufficiently elucidated. Basically, receptors are divided into two types: “capsule-shaped” and “free nerve ending structure” with branched nerve endings. This difference is how fast a stimulus is transmitted to the brain. It is related to the difference between receiving one stimulus or receiving multiple stimuli (referred to as “polymodal receptor”).

On the other hand, the sensory receptors are classified into the following four types according to the dynamic component of the stimulus based on the result of acquiring the response of each nerve by sending electricity from the top of the skin to the minute part by the `` microneurography '' You can also
1) Meissner body: Fast adaptation type I unit (FAI) …… Stimulus velocity component
2) Pacini body: Fast adaptation type II unit (FAII) …… Acceleration component
3) Merkel touch panel: slow adapting type I unit (SAI) ... speed and displacement
4) Ruffin terminal: Late adaptation type I unit (SAII) …… Displacement only

  In this case, the receptive resolution of sensory receptors 1) and 3) is several millimeters, and 2) and 4) are blurred receptive field boundaries compared to 1) and 3). However, peripheral adaptation that occurs in sensory receptors cannot be categorized because it is influenced by the energy conversion process of the receptor membrane, ion permeation mechanism, and synaptic transmission characteristics between receptor cells and sensory fibers. . “Adaptation” means that if a stimulus of the same strength is continuously applied to the sensory organ, the strength of the subjective sensation gradually decreases and approaches a certain value. It has been found that the sensory nerve with fast adaptation shows a response only at the rise of the stimulus, and the one with slow adaptation produces an impulse during the stimulus.

  By combining these sensory receptors, the temporal nature of the stimulus can be identified and is shown in the table below.

It can be summarized as follows. By the way, regarding the relationship between sensory receptors and existing sites in the above table, the Patini body exists in the upper layer than the dermis layer, the Mysnel body is interposed between the dermis layer and the dermal papilla, and the Merkel body is It means that it is interposed between the dermal papilla and the epidermis, the Ruffini body is interposed between the epidermis and the dermis layer, and the free nerve endings are present below the dermis layer.

(1-1-3) Sensory molecular mechanisms Next, we will examine the physical mechanism by which sensory receptors such as mechanoreceptors and thermoreceptors produce sensory information. Explained.

  In recent years, molecules have been identified that appear to be related to tactile sensation in mammals. Brain sodium cannel1 (BNC1), a sodium channel protein (ion channel), is expressed in the free nerve endings distributed around the hair root, but it is mildly mechanically stimulated compared to animals that blocked this protein expression and normal animals. Response to is reduced in blocked animals. In the living body, ion channels are opened by mechanical stimulation, and a receptor potential is generated. This causes depolarization of the nerve cell membrane, and a nerve action potential is generated, whereby sensory stimulation is transmitted to the center. In addition, other ion channel proteins expressed on nerve endings and Merkel touch plates have been identified. Protein molecules with similar functions that have high homology to these proteins are also expressed in nematodes, and this mechanism is well preserved in the process of biological evolution.

  Similarly, in the sense of warmth, it is known that the free nerve ending is a receptor, and it is considered that a sodium channel protein exists, and this protein controls the function of the aforementioned Lorentini bottle, that is, It is considered to be a Lorenti functional protein (an electrochemical property similar to a piezoelectric material).

(1-1-4) Mechanism of sensory presentation by application of electric field Next, a mechanism of sensory expression when an electric field is applied to the sodium channel protein will be described.

  Along with the vibration of the electric field applied to the living body from the outside, the substances constituting the living body also vibrate electrically. Each electrical vibration of each material is involved in the dielectric constant. If the vibration frequency is increased here, it may be impossible to follow the frequency. Then, at a frequency equal to or higher than that frequency (hereinafter referred to as the following boundary frequency), the contribution to the dielectric constant drops off, and the dielectric constant decreases in proportion to the amount of the portion.

  That is, when the dielectric constant exceeds the following boundary frequency, it gradually decreases by Δ. This phenomenon is called dielectric dispersion. On the other hand, the dielectric loss factor shows a peak due to dielectric absorption when the frequency is at the characteristic frequency (cited by Naoko Tanida, et al., “Dielectric constant and biological body”, Ochanomizu University, Life Engineering Research, 3 ( 2), pp256-259).

  Here, it is known that there are three types of dielectric dispersion in living tissue depending on the frequency. The first is called α dispersion depending on the ion atmosphere of particles such as proteins, the second is called β dispersion depending on the electric capacity of the cell membrane, and the third is biological tissue. This is called γ dispersion, which depends on the bound water. What is noticed here is that α dispersion is for proteins and β dispersion is for cell membranes, both of which are directly related to ion channels.

  Hereinafter, α and β dispersion will be specifically described as a mechanism for selectively causing stimulation to sensory nerve tissue terminals.

(1-1-4-1) α dispersion (Schwarz-Grosse)
Particles such as proteins have a negative charge. Surrounding it is an ion atmosphere (thickness of about 1 [nm]) by counter ions. Dielectric dispersion (α dispersion) occurs when this ion atmosphere is polarized by an applied electric field (reference document 1: G. Schwarz, “A theory of the low frequency dielectric dispersion of colloidal particles in electrolyte solution”, J. Phys. Chem. , 66, 2636 (1962), cited reference 2: C. Grosse, KRFoster, “Permittivity of a suspension of charged spherical particles in electrolyte solution”, J. Phys. Chem., 91, 3073 (1987)).

The following boundary frequency of this α dispersion is approximately 100 [Hz]. The α dispersion magnitude α _Δε and the α dispersion relaxation time α _τ are defined as follows: a radius of a particle such as a protein is a, an ion diffusion constant is D, a particle volume fraction is γ, a wavelength Where λ is

Can be asked according to.

  As a specific mechanism of such α dispersion, the ionic atmosphere surrounding the sodium channel protein of the nerve terminal tissue is polarized by the applied quasi-electrostatic field, and the ionic atmosphere is polarized to polarize the protein itself at the sensory nerve tissue terminal. Thus, the ion channel is opened and a receptor potential is generated, which causes depolarization of the nerve cell membrane, and the action potential of the nerve is generated, so that sensory stimulation is transmitted to the center.

(1-1-4-2) β dispersion (Pauly-Schwan)
When the frequency is continuously increased beyond the following boundary frequency of α dispersion (about 100 [Hz]), β dispersion occurs (reference document 1: H. Pauly, HPSchwan, “Uber die Impedanzeiner Suspension von kugelformigen Teilchenmit einer Schale” , Z. Naturforsch., 14B, 125, (1959), Citation 2: HP Schwan, G. Schwarz, JMaczuk, H. Pauly, “On the low frequency dielectric dispersion of colloidal particles in electrolyte solution”, J. Phys. Chem. 66,2626-2636 (1962)).

This β dispersion is due to the electric capacity of the cell membrane of the cells in the living tissue, and the following boundary frequency is about 500 [kHz]. In addition, the β dispersion magnitude β _Δε and the β dispersion relaxation time β _τ are defined such that the radius of the cell in the living tissue is b (approximately 10 microns), and the electric capacity per unit area in the cell is _cm. (Approx. 1μF / cm ² )

Can be asked according to. This equation (2) is obtained with respect to the average of the electrical conductivity of the intracellular fluid and the extracellular fluid, and the volume fraction γ of the particles is the volume fraction of the whole cell tissue. The relaxation time _βτ is characterized in that it is determined from the resistance of the intracellular fluid and the volume of the cell membrane.

  As a specific mechanism of such β dispersion, two hypotheses can be considered, which is a polarization action on the cell membrane of the sensory nerve tissue terminal tissue, which opens an ion channel, or an ion channel protein characterized by α dispersion. Rather than the rich nerve endings, rather, it acts on the mechanism that amplifies ion channel changes near the sensory nerve tissue endings by acting on the cell membrane.

(1-1-5) Experiment of quasi-electrostatic occurrence of temperature sensation In general, the characteristics of temperature sensation are conveyed by two independent receptor systems, i) temperature and cold. ii) The area where the temperature is felt is scattered on the skin. Some spots feel warm only (hot spot warm spot), others feel cold only (cold spot cold spot). There are more cold spots than hot spots. iii) Units that ignite when electrophysiologically hot and those that ignite when cold are found. iv) It is known that when a temperature stimulus is applied to the skin, three nerve fibers (units) of a) cold fiber, b) warm fiber, and c) pain sensory fiber work.

  That is, as shown in FIG. 1, when it is very cold, only the pain fiber is ignited, and the impulse of the pain fiber is reduced at about 15 ° C., and the cold fiber is activated. Furthermore, at 25 ° C. or higher, cold fiber receptors are hardly stimulated, and warm fibers are ignited. Next, a specific phenomenon is observed in which cold fibers and warm fibers ignite to the same extent at 33 ° C. (32.5 to 33.5 ° C.). In this case, even if a temperature stimulus is applied to the skin, neither the cold sense nor the warm sense is presented, and the temperature at this time is called an indifferent temperature.

  In addition, warm fiber receptors are gradually not stimulated at around 45 ° C. At the same time, the cold fiber ignites again. This phenomenon in which cold sensation is caused by a high temperature stimulus of 45 ° C. or higher is called paradoxical cold sensation. At the same time, pain fibers also ignite.

  Based on this, a quasi-electrostatic field of several hertz to several tens of hertz is generated from the electrode, and the result of verifying the characteristics of the temperature sensation presented to the human body existing in the electric field is shown in FIG. In FIG. 2, the temperature sensation does not occur at several tens of hertz, but when the frequency falls below 5 [Hz], a temperature sensation close to the body temperature starts to appear, and a verification result is obtained that peaks at around 3 [Hz] to 4 [Hz]. It was. It can be seen that the frequency of the quasi-electrostatic field and the number of peak impulses of the warm fiber are almost the same (the part indicated by a circle in the figure).

  As described above, this is due to the α-dispersion in the sodium ion channel protein (a lentil functional protein (an electrochemical property similar to a piezoelectric material)) due to the applied low-frequency quasi-electrostatic field. When the atmosphere is polarized, an ion channel opens and a receptor potential is generated, which causes a depolarization of the nerve cell membrane and generates a nerve action potential. As a result, a sensory stimulus is transmitted to the center, and a temperature sensation ( It is thought that (warm sense) is presented.

  In addition, as shown in FIGS. 1 and 2, the sensory nerve tissue ends were resonated (adapted) to a quasi-electrostatic field of 3 [Hz] to 4 [Hz], so that the warm sense was presented. Resonance with a quasi-electrostatic field of a specific frequency (9 [Hz] to 10 [Hz] for cold sensation, 6 [Hz] to 7 [Hz] for pain sensation), etc. It is thought that it is presented by the same mechanism, and at least at the sensory nerve tissue terminal, it resonates with a quasi-electrostatic field having a frequency less than the following boundary frequency (100 [Hz]) of α dispersion and senses corresponding to the frequency. It is understood that is considered to be presented.

  Based on the above considerations and facts, it is utilized that the sensory nerve tissue terminal of the living body has a specific electric field sensitivity. That is, if a quasi-electrostatic field having a frequency corresponding to the sensation (for example, a quasi-electrostatic field of 3 to 4 [Hz] in the case of temperature sensation) is applied to the sensory nerve tissue end, the applied quasi-electrostatic field actually It will be possible to present a specific feeling that is not.

(1-2) Quasi-electrostatic field The intensity of the quasi-electrostatic field is inversely proportional to the cube of the distance from the electric field generation source. This means that the quasi-electrostatic field has a high resolution with respect to distance. By using this property of the quasi-electrostatic field, the reach distance of the quasi-electrostatic field applied to the inside of the human body via the electric field generation source (that is, to the sensory nerve tissue end and other nerve tissues intervening inside the human body) Can be selectively applied to the neural tissue as a target. Here, before explaining the reach distance control method in the quasi-electrostatic field (hereinafter referred to as quasi-electrostatic field distance control method), the properties of the quasi-electrostatic field will be described first.

(1-2-1) Properties of quasi-electrostatic field An electric field includes a radiated electric field linearly inversely proportional to a distance from an electric field generating source such as a dipole antenna, and an induced electromagnetic field inversely proportional to the square of the distance from the electric field generating source. It is generated as a combined electric field with a quasi-electrostatic field that is inversely proportional to the cube of the distance from the electric field generating source.

  When the relationship between the relative intensity of each of the radiation electric field, the induction electromagnetic field, and the quasi-electrostatic field and the distance is graphed, the result shown in FIG. However, in FIG. 3, the relationship between the relative intensity and distance of each electric field at 1 [MHz] is shown on a logarithmic scale.

  As is clear from FIG. 3, there is a distance (hereinafter referred to as an intensity boundary point) where the relative strengths of the radiated electric field, the induction electromagnetic field, and the quasi-electrostatic field are equal. In this case, the radiated electric field dominates farther than the intensity boundary point (a state larger than the intensity of the induction electromagnetic field and quasi-electrostatic field), whereas the quasi-electrostatic field dominates near the intensity boundary point (radiated electric field). Or a state where the intensity is greater than the intensity of the induction electromagnetic field.

  This intensity boundary point is expressed as follows when Maxwell's equation is derived from the viewpoint of electric field strength and the distance is r [m] and the wave number is k [1 / m].

Can be expressed as

  The wave number k in equation (3) is expressed as follows when the propagation velocity of the electric field in the medium is v [m / s] and the frequency is f [Hz].

The electric field propagation velocity v can be expressed as follows, where the light velocity is c [m / s] (c = 3 × 10 ⁸ ) and the dielectric constant of the medium is ε.

Since the intensity boundary point can be expressed as the following equation, the equation (4) and (5) are substituted into equation (3).

Can be expressed as

  As can be seen from this equation (6), the frequency is closely related when the space of the quasi-electrostatic field, which has a higher strength than the radiated electric field and the induced electromagnetic field, is closely related. The more the space of the quasi-electrostatic field that is in a stronger state than the radiated electric field and the induction electromagnetic field is larger (that is, the distance to the intensity boundary point shown in FIG. 3 is longer as the frequency is lower ( On the other hand, the higher the frequency, the narrower the space of the quasi-electrostatic field that is stronger than the radiated and induced fields (ie, as shown in FIG. 3). The distance to the intensity boundary point becomes shorter as the frequency becomes higher (that is, it moves to the left).

  For example, when 10 [MHz] is selected, assuming that the relative permittivity of the human body is uniformly 50, the quasi-electrostatic field is dominant near 0.675 [m] according to the above equation (6). become. When such 10 [MHz] is selected, the relationship between the relative intensity of each of the radiated electric field, the induction electromagnetic field, and the quasi-electrostatic field and the distance is graphed, and the result shown in FIG. 4 is obtained.

  As is clear from FIG. 4, when the reach distance of the quasi-electrostatic field from the electric field generation source is 0.01 [m], the quasi-electrostatic field from the generation source to the point of 0.01 [m] The intensity is about 18.2 [dB] larger than the induction electromagnetic field. Therefore, the quasi-electrostatic field in this case can be regarded as having no influence of the induction electromagnetic field and the radiation electric field.

  Here, using the properties of the quasi-electrostatic field as described above, for example, as shown in FIG. 5, the reach distance of the quasi-electrostatic field is 0.01 [m] from the surface of the human body at intervals of 0.001 [m]. A quasi-electrostatic field reach control method for controlling inward will be described.

(1-2-2) Quasi-electrostatic field reach control method As shown in FIG. 5, a frequency of 10 [MHz], for example, is 0.001 [m], which is the minimum reach from the surface of the human body, as a reference frequency. Allocation is performed so that a large frequency is sequentially allocated every 0.001 [m]. In this way, the reach of the quasi-electrostatic field can be controlled by the frequency.

  However, in this case, the higher the frequency, the narrower the space in which the quasi-electrostatic field is dominant (that is, the intensity boundary point shown in FIG. 3 moves to the left). In the vicinity, the difference in intensity between the quasi-electrostatic field and the induction electromagnetic field becomes smaller than 18.2 [dB], so that the intensity becomes unstable according to the depth from the human body surface, and thus presents a specific sense. It will also happen that you can't.

In this case, the intensity boundary point corresponding to each frequency f _(r) of 10 [MHz] or more to the intensity at a distance (0.001 [m] from the electric field generation source) corresponding to the frequency of 10 [MHz]. If the outputs are adjusted so that they match, the intensity according to the depth of the application target intervening in the human body becomes constant, so that a specific sense can be presented reliably.

That is, when a sine wave signal is output to an electrode as an electric field generation source and a quasi-electrostatic field that oscillates according to the frequency of the sine wave signal is generated from the electrode, a coefficient for adjusting the output (hereinafter referred to as this). Assuming that the output adjustment coefficient is A _(r) , the quasi-electrostatic field intensity E _(r) at the distance r [m] from the electrode is given by

Can be expressed as When the reach distance r of the equation (7) is transformed in accordance with the above equation (6) regarding the intensity boundary point,

Can be expressed as

And the intensity at the reach distance (0.001 [m] from the electrode) corresponding to the frequency of 10 [MHz] is the intensity of the intensity boundary point corresponding to each frequency f _(r) of 10 [MHz] or more. Since it is sufficient to determine the frequency f _(r) so as to match,

When this equation (9) is rearranged,

It becomes. Using this equation (10), it is possible to determine the output adjustment coefficient A _(r) to be adjusted when outputting a sine wave signal having a frequency f _(r) corresponding to the reach distance r.

Further, for each frequency f _(r) corresponding to each reaching distance r from the electric field generating electrode every 0.001 [m],

When the output coefficient A _(r) of the equation (11) is modified according to the above equation (10), the following equation is obtained:

Then, the following formula which rearranged this formula (12)

Can be determined.

  When the quasi-electrostatic field generated based on the above-described conditions determined in this way is graphed, the result shown in FIG. 6 is obtained. However, in FIG. 6, in order to make it easy to see, predetermined reachable distances (0.001 [m], 0.002 [m], 0.004 [m], 0.006 [m], 0.008, not all of the reachable distances every 0.001 [m]). [m], 0.01 [m]) only the quasi-electrostatic field is shown, and in FIG. 6A, the vertical axis (electric field strength) is shown, and in FIG. 6B, the vertical axis (electric field strength) and the horizontal axis ( (Distance) is shown on a logarithmic scale. As is apparent from FIG. 6, when the electric field strength of the quasi-electrostatic field is constant at a predetermined reference, for example, an intensity boundary point, the reach distance is selectively selected depending on the frequency in a state where the strength of the quasi-electrostatic field is dominant. It can also be seen that the target nerve tissue inherent in the human body can be adaptively applied.

  Note that the case where the quasi-electrostatic field is generated from the electric field generating electrode at intervals of 0.001 [m] (FIG. 5) has been described above. Is selected in consideration of, for example, the depth of the neural tissue intervening from the surface of the human body. In this case, the output adjustment coefficient and the frequency are determined after deriving the equations (10) and (13) based on the selection result.

(2) Configuration of Sensory Stimulation Device FIG. 7 shows the sensory stimulation device 1 according to the present embodiment. The sensory stimulation device 1 includes, for example, a pair of electrodes 2a and 2b arranged in a non-contact state at a predetermined position on the human body surface, a quasi-electrostatic field generating unit 3, and a sensory-specific nerve stimulation dictionary unit 4. .

  The sensory nerve stimulation dictionary unit 4 stores a plurality of frequencies for expressing α dispersion or β dispersion for sensory nerve terminals and a waveform state pattern (hereinafter referred to as a nerve stimulation waveform pattern). Has been. These frequencies are equal to or less than the following boundary frequency (100 [Hz]) of α dispersion, and are selected according to the sensation, and each neural stimulation waveform pattern defines the rising and falling speeds of the frequency according to the sensation. Has been.

  That is, for the presentation of warm sense, a frequency of 3 to 4 [Hz], and a nerve stimulation waveform pattern (waveform pattern related to 25 ° C. to 45 ° C. in FIG. 1 or FIG. 2) with a gradual rise and fall of the frequency Are stored, and for the presentation of cold sensation, the frequency of 9 to 10 [Hz], and the neural stimulation waveform pattern in which the rising and falling of the frequency are steeper than the neural stimulation waveform pattern of warm sense (FIG. 1 or FIG. 2 is stored in memory, and for the presentation of pain sensation, the frequency of 6-7 [Hz] and the neural stimulation waveform with the same rise as the neural stimulation waveform pattern of cold sensation are stored. A pattern (a waveform pattern related to 0 ° C. to 15 ° C. in FIG. 1 or FIG. 2) is stored and held, and in addition to this, a frequency of tens to 100 [Hz] or less is used for presentation of cold sensation and pain sensation, and for presentation The most up to date Steep nerve stimulation waveform pattern and (waveform pattern of 45 ° C. after 1 or 2) is stored and held.

  On the other hand, as shown in FIG. 7, the quasi-electrostatic field generating unit 3 outputs a plurality of sine wave signals (hereinafter referred to as alternating signals) respectively corresponding to a plurality of frequencies to the electrodes 2a and 2b. (Hereinafter referred to as an alternating signal output unit) 10 and an output adjusting unit 11 that controls the output of the alternating signal output unit 10.

  In this case, in the alternating signal output unit 10, the frequency of each sine wave signal is set in advance according to the above-described equation (10), and the relationship between these frequencies and distances is as described in (1-2) above. Similar to the case described above, the minimum reference frequency value is set in correspondence with the minimum reach distance, and each frequency value is set in correspondence with the reach distances that are sequentially increased at predetermined intervals. Further, the output adjustment unit 11 stores and holds an output adjustment coefficient for each frequency value calculated in advance according to the above equation (13) as a table (hereinafter referred to as an output adjustment coefficient table).

  In the quasi-electrostatic field generating unit 3, an arbitrary sine wave signal is selected from the alternating signal of the alternating signal output unit 10, and the selected sine wave signal is adjusted with a corresponding output adjustment coefficient based on the output adjustment coefficient table. After that, it outputs to the electrodes 2a and 2b.

  Accordingly, the quasi-electrostatic field generating section 3 can selectively switch the reach distance of the quasi-electrostatic field in a state where the strength of the quasi-electrostatic field generated from the electrodes 2a and 2b is always dominant. In this case, since the quasi-electrostatic field generating unit 3 can control the reach distance of the quasi-electrostatic field having a high resolution with respect to the distance, even if it is a superficial sensory nerve tissue terminal, In contrast, sensory stimulation can be performed locally and without contact.

  Here, the quasi-electrostatic field generating unit 3 applies a quasi-electrostatic field composed of a combination of an arbitrary frequency and a nerve stimulation waveform pattern among a plurality of combinations of frequencies and nerve stimulation waveform patterns to the sensory nerve tissue terminal. Examples of the application method include first and second application methods.

(2-1) First Application Method First, the first method will be described. In this first method, when a quasi-electrostatic field having a frequency corresponding to a desired sense is applied, only one electrode 2a is included so that the application target is included within the reach distance corresponding to the quasi-electrostatic field having the frequency. In this state, a predetermined operation for determining a desired frequency and nerve stimulation waveform pattern is performed from an operation unit (not shown) of the quasi-electrostatic field generating unit 3.

  In this case, the quasi-electrostatic field generating unit 3 has a quasi-electrostatic field having a strength greater than that of the radiated electric field and the induction electromagnetic field at the reach distance corresponding to the frequency of the temperature sense selected at this time (the broken line range in the figure). An electric field is applied so as to have a neural stimulation waveform pattern.

  That is, the quasi-electrostatic field generating unit 3 selects the frequency of the sensation and the neural stimulation waveform pattern from the sensory-specific neural stimulation dictionary unit 4 and sends this as pattern data to the alternating signal output unit 10 and the output adjustment unit 11. .

  The alternating signal output unit 10 selects a sine wave signal having a corresponding frequency from the alternating signal based on the pattern data, generates the sine wave signal as a pattern signal corresponding to the neural stimulation waveform pattern, and generates this as the electrode 2a. Output to.

  At this time, the output adjustment unit 11 adjusts the output of the pattern signal with the output adjustment coefficient corresponding to the frequency of the pattern data based on the output adjustment coefficient table.

  In this case, a quasi-electrostatic field that vibrates in accordance with the frequency (3 to 4 [Hz]) of the pattern signal and the waveform pattern is generated from the electrode 2a with a greater intensity than the radiated electric field and the induction electromagnetic field, and the quasi-static The sensory nerve tissue is applied to the terminal of the sensory nerve tissue that is exposed on the human arm subjected to the electric field. At the sensory nerve tissue end, depolarization occurs and a nerve action potential is generated. As a result, a sensory stimulus is transmitted to the center and a temperature sensation (warmth) is presented.

(2-2) Second Application Method Next, the second method will be described. As this second method, for example, as shown in FIG. 9, two electrodes 2a and 2b are arbitrarily arranged, and in this state, a desired sensation can be obtained from the operation unit (not shown) of the quasi-electrostatic field generating unit 3. While determining the frequency and the nerve stimulation waveform pattern, for example, as shown in FIG. 9, a first distance DIS1 from the electrode 2a to the application target P and a second distance DIS2 from the electrode 2b to the application target P are input. A predetermined operation (hereinafter referred to as sensory stimulus input operation) is performed.

  In this case, the quasi-electrostatic field generating unit 3 is the reach distance (the broken line range in the figure) including the application target P, and the interference result at the application target P is selected at this time, for example, the nerve stimulation of warm sense The electrode 2a and the electrode 2a so as to be a cold nerve stimulation waveform pattern (waveform pattern related to 15 ° C. to 33 ° C. in FIG. 1 or FIG. 2) having a steep rising frequency (9 to 10 [Hz]) than the waveform pattern. A quasi-electrostatic field is applied from both electrodes 2b.

  That is, the quasi-electrostatic field generating unit 3 selects a cold sense frequency and neural stimulation waveform pattern from the sensory-specific neural stimulation dictionary unit 4, sends this as pattern data to the alternating signal output unit 10, and inputs sensory stimulation. The first distance DIS1 and the second distance DIS2 input by the operation are sent to the alternating signal output unit 10 as distance data.

  The alternating signal output unit 10 determines a sine wave signal having a frequency corresponding to an arrival distance longer than the first distance DIS1 in the distance data as a sine wave signal to be given to the electrode 2a.

Then, the alternating signal output unit 10 assumes that the frequency of the sine wave signal determined at this time is f ₁ and the frequency in the pattern data (cool sense frequency) is f _beat ,

Accordingly, the frequency f ₂ is calculated such that the difference between the frequency f ₁ and the frequency f ₂ becomes the frequency f _beat .

Here, the alternating signal output unit 10, when reaching a distance corresponding to a frequency f ₂ which is calculated this time was a less than two distance DIS2 at the distance data, the frequency f ₁ to be supplied to the electrodes 2a previously determined after re-determine the sine wave signal, to re-calculate a sinusoidal signal of frequency f ₂ in accordance with again (14).

Alternating signal output unit 10 on the other hand, the second when the a distance DIS2 above, the frequency f _2, which is calculated this time sinusoidal signal electrode 2b of the reaching distance is distance data corresponding to the frequency f ₂ Is determined as a sine wave signal to be given to

The reach distances corresponding to the frequency f ₁ and the frequency f ₂ determined in this way are both distances including the distances DIS1 and DIS2 from the electrodes 2a and 2b to the application target P, and these frequencies f ₁ and the difference between the frequency f ₂ are in a relation of frequency (frequency of the cold sensation) f _beat in the pattern data.

Then, the alternating signal output unit 10 sends the frequency f ₁ and the frequency f ₂ to the output adjustment unit 11 as frequency determination data, and outputs each sine wave signal of the frequency f ₁ and the frequency f ₂ to the nerve stimulation waveform pattern. It generates as a pattern signal corresponding to the rising, and outputs it to the corresponding electrodes 2a, 2b.

  At this time, the output adjustment unit 11 adjusts the output of each corresponding sine wave signal with the output adjustment coefficient corresponding to the frequency of the frequency determination data based on the output adjustment coefficient table.

  In this case, for example, as shown in FIG. 10, the quasi-electrostatic field oscillating according to the frequency of 100 [Hz] is applied from one electrode 2a in a state superior to the radiated electric field and the induced electromagnetic field. The quasi-electrostatic field generated from the other electrode 2b and oscillating in accordance with the frequency of 110 [Hz] is superior to the radiated electric field and the induced electromagnetic field. ).

  In the application target P, the frequency of 100 [Hz] and the frequency of 110 [Hz] interfere with each other. As a result of this interference, as shown in FIG. Since the quasi-electrostatic field corresponding to the neural stimulation waveform pattern of cold sensation having a frequency of [Hz] -100 [Hz]) is applied, at the sensory nerve tissue end near the application target P, As a result, depolarization occurs and a nerve action potential is generated. As a result, a sensory stimulus is transmitted to the center and a cold sensation is presented.

  As described above, in the second method, two types of signals having different frequencies are used, the reach of the quasi-electrostatic field corresponding to the frequency includes the sensory nerve tissue end, and the difference between the frequencies corresponds to the sense. Are generated so as to have the same frequency, and these are output to the electric electrodes 2a and 2b, so that the power consumption is larger than that of the first method and the quasi-electrostatic field is not as simple as the electrode 2b is used. Therefore, the quasi-electrostatic field can be applied to the sensory nerve tissue end regardless of the depth inside the human body. Therefore, as compared with the first method, an advantage is that the quasi-electrostatic field can be reliably applied to the sensory nerve tissue terminal without forcing the arrangement position of the electrodes 2a and 2b with respect to the sensory nerve tissue terminal to be applied. There is an advantage that a sense can be presented more easily by reducing the restraint until the quasi-electrostatic field is applied to the human body.

  In this way, the quasi-electrostatic field generating unit 3 applies a quasi-electrostatic field corresponding to the nerve stimulation waveform pattern selected by the first or second method via the operation unit (not shown) at the sensory nerve tissue terminal. By controlling as described above, electrical stimulation is applied locally and non-invasively to the sensory nerve tissue end, and as a result, an unrealistic sensation can be presented.

(3) Operation and effect according to the present embodiment In the above configuration, the sensory stimulation device 1 applies an electric field of 100 [Hz] or less to the terminal of the sensory nerve tissue of the living body.

  Therefore, in this sensory stimulation device 1, since the electric field can be applied to the sensory nerve tissue terminal with an extremely small current with respect to the sensory nerve tissue terminal without requiring a coil for generating a magnetic field, the power consumption can be reduced. In this case, since the frequency at which the superficial sensory nerve tissue ends resonate is applied, the sensation can be presented more efficiently than the magnetic field.

  In this case, the sensory stimulation device 1 selects an arbitrary frequency from a plurality of frequencies corresponding to the sense, and generates a signal corresponding to the selected frequency as a pattern signal.

  Therefore, the sensory stimulation device 1 can present a specific sensation that does not actually exist to the human body to which the quasi-electrostatic field is applied according to the user's intention.

Furthermore, in this case, the sensory stimulation device 1 can present the sense more reliably by generating the pattern signal in consideration of not only the frequency corresponding to the sense but also the rise of the frequency.

  According to the above configuration, the quasi-electrostatic field is weaker than that of the conventional method in which a sensory stimulation is performed in a non-contact manner only on the nerve terminal portion at a predetermined depth from the living body epidermis and a large current is passed through the 8-shaped coil. Since the components are used, the power consumption can be reduced, so that the sense can be stimulated more easily than in the past, and thus the usefulness can be increased.

(4) Other Embodiments In the above-described embodiment, the case where the sensor is applied to the sensory nerve tissue end in the human body has been described. However, the present invention is not limited to this, and the main point is the electric field. You may make it apply to the sensory nerve tissue terminal which has various other in-vivo insides, such as fish, an amphibian, a reptile, a bird, or a mammal which has a sensitive sensory nerve tissue terminal.

  In this case, the case where the quasi-electrostatic field is applied to the sensory nerve tissue terminal has been described. However, the present invention is not limited to this, and the object is to use the electric field component instead of the magnetic field component in the radiated electric field and the induction electromagnetic field. The radiation electric field and the induction electromagnetic field may be applied to the sensory nerve tissue terminal. In this case, compared to the quasi-electrostatic field generated as a pure electric field in response to vibration, the radiated electric field and the induction electromagnetic field have two different effects of the eddy current due to the electric field and the magnetic field, and the dielectric constant and conductivity of individual tissues. Since the interaction is complicated depending on the rate or the like, it is possible to reduce the efficiency when accurately presenting the sensation compared to the quasi-electrostatic field.

  Further, in the above-described embodiment, the case where the pair of electrodes 2a and 2b are applied as the electric field generating means (electric field generating source) has been described. For example, a directivity limiting shield that limits the property to a linear shape may be provided on the electrodes 2a and 2b. In this way, since the quasi-electrostatic field can be applied pinpoint to the sensory nerve tissue terminal, it is possible to avoid applying stimuli in parallel to the set rather than to individual nerves. As a result, the sense can be presented more efficiently and the usefulness can be enhanced.

  Furthermore, in the above-described embodiment, a signal for generating a predetermined sensation in the living body is used as a selection means, and a signal having a frequency and a waveform pattern for causing the living body to generate a predetermined sensation is selected. As described above, the present invention does not necessarily require selection of both, and it is sufficient to select a signal having a frequency for causing a living body to have a predetermined sensation. Even in this case, the same effect as that of the above-described embodiment can be obtained.

  Furthermore, in the above-described embodiment, as an electric field applying means for applying an electric field corresponding to the selected signal to the sensory nerve terminal, the relationship between each frequency value calculated in advance according to the equation (11) and the output adjustment coefficient Is stored and held as a table, and the output adjustment unit 11 that adjusts the output of the signal based on this table is applied. However, the present invention is not limited to this, and each time according to the equation (11) The output adjustment coefficient may be calculated by a calculation method other than the expression (11).

  Furthermore, in the above-described embodiment, the first distance DIS1 (FIG. 9) from the electrode 2a to the application target P and the second distance DIS2 (FIG. 9) from the electrode 2b to the application target P are set by the sensory stimulus input operation. Although the case where it was made to input beforehand was described, this invention is not restricted to this, You may make it search the application target P automatically, without inputting the said distance.

  Specifically, for example, a pair of detection electrodes for detecting a quasi-electrostatic field generated from the electrodes 2a and 2b are provided in the vicinity of the electrodes 2a and 2b for electric field generation. A measuring unit for measuring the change is provided in the quasi-electrostatic field generating unit 3.

  Then, the quasi-electrostatic field generating unit 3 causes the output adjusting unit 10 and the output adjusting unit 11 to sequentially generate a sine wave signal having a frequency corresponding to a minimum reach distance from a sine wave signal corresponding to a minimum reach distance in a predetermined cycle. After generating and adjusting the output, it is applied to the electrodes 2a and 2b, so that the reach distance of the quasi-electrostatic field generated from the electrodes 2a and 2b is sequentially increased in a predetermined cycle. On the other hand, the quasi-electrostatic field generation unit 3 detects the interference state of the quasi-electrostatic fields generated from the electrodes 2a and 2b based on the change in impedance measured by the measurement unit, and at the detection time, Stop the switching of the reach of the electrostatic field. In this way, the first distance DIS1 (FIG. 9) from the electrode 2a to the application target P and the second distance DIS2 (FIG. 9) from the electrode 2b to the application target P are input in advance by a sensory stimulus input operation. Without any problem, it is possible to automatically apply an electrical stimulus to the application target P to present a sense.

  Furthermore, in the above-described embodiment, the case where the quasi-electrostatic field generating unit 3 is provided inside the sensory stimulation device 1 has been described. However, the present invention is not limited thereto, and the quasi-electrostatic field generating unit 3 is separately provided. You may make it provide as a body (electric field generator).

  The present invention can be used when stimulating a sensory nerve tissue of a living body, for example, in the virtual reality field or the medical field.

It is a graph which shows the relationship between the firing frequency of three nerve fibers, and temperature. It is a graph which shows verification by experiment. It is a basic diagram which shows the relative intensity | strength change (1 [MHz]) of each electric field according to distance. It is a basic diagram which shows the relative intensity | strength change (10 [MHz]) of each electric field according to distance. It is a basic diagram with which it uses for description of a quasi-electrostatic field reach distance control method. It is a graph which shows each quasi-electrostatic field obtained by the quasi-electrostatic field reach control method. It is a block diagram which shows the structure of a sensory stimulation apparatus. It is a basic diagram which shows the mode (1) of a quasi-electrostatic field application. It is a basic diagram which shows the mode (2) of a quasi-electrostatic field application. It is a wave form diagram with which the production | generation of the nerve stimulation waveform pattern of a tactile sensation is provided.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Sensory stimulation apparatus, 2a, 2b ... Electrode, 3 ... Quasi-electrostatic field generation | occurrence | production part, 4 ... Sensory-specific nerve stimulation dictionary part.

Claims (6)

An electrode that is an electric field generation source and is in close contact with a living body;
Among a plurality of frequencies assigned to sense to cause to the biological, selection means for selecting a signal of a specified frequency,
The signal selected by the selection means is applied to the electrode, with respect to sensory nerve endings in the biological, the electric field applying means for applying the quasi-electrostatic field of high intensity than the radiation field and the induction field A sensory stimulation device characterized by comprising. The electric field applying means is
Of the plurality of frequencies, the output of the signal is adjusted so that the quasi-electrostatic field strength other than the reference frequency becomes the quasi-electrostatic field strength of the reference frequency.
The sensory stimulation device according to claim 1. The signal has a waveform pattern that rises faster to the peak as the frequency is higher.
The sensory stimulation device according to claim 1. The plurality of frequencies is 100 [Hz] or less .
Sensory stimulation device according to 請 Motomeko 1. The selection means is:
Select a signal of 3 [Hz] to 4 [Hz] that is assigned to the sense of warmth
Sensory stimulation device according to 請 Motomeko 1. The selection means is:
The frequency difference in a plurality of signals to be a selection target is a frequency assigned to the sense and to reach the respective quasi-electrostatic field according to the plurality of signal is a predetermined distance or more, the plurality of Select the signal
The electric field applying means is
Be applied to the sensory nerve endings of each of the quasi-electrostatic field according to a plurality of No. signals selected by said selecting means from different directions
Sensory stimulation device according to 請 Motomeko 1.

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