Olfactory adjustment device, olfactory display, and olfactory adjustment method

Abstract

To realize an olfactory adjustment device that can instantly change the intensity of odors. [Solution] The olfactory adjustment device (20) comprises a first electrode and a second electrode (21) positioned such that the nasal cavity (12) is located between the first electrode (21) and the second electrode (22), and a current supply unit (23) that changes the odor intensity of the sense of smell by supplying current between the first electrode and the second electrode.

Description

Technical Field

[0001] The present invention relates to an olfactory regulation device, an olfactory display, and an olfactory regulation method for regulating olfaction by electrical stimulation.

Background Art

[0002] When an electrical stimulus is applied to a human sensory organ, various sensations are known to be activated or suppressed. Representative examples include GTS (Galvanic Taste Stimulation) that activates or suppresses taste, or tactile electrical stimulation.

[0003] However, research on electrical stimulation for activating or suppressing olfaction is limited, and many studies have difficulties in terms of the reproducibility of the phenomenon. Previous studies can be broadly classified into those that do not use odorant substances and those that use odorant substances for olfactory electrical stimulation.

[0004] Olfactory electrical stimulation without using odorant substances selects, as the stimulation target, the olfactory bulb where the axons of olfactory nerves converge, or the cerebral cortex that may be the site for processing olfaction. Inevitably, most of the studies involve invasively placing electrodes (Non-Patent Documents 1, 2, 3, 4). However, these research results generally show a low probability of odor expression and unclear odor quality, and it is difficult to say that they are stable olfactory presentation methods.

[0005] On the other hand, there are also examples where non-invasive electrical stimulation without using odorant substances has successfully induced chemosensation in the nasal cavity. It has been reported that by placing electrodes around the nose and applying electrical stimulation, a stimulating odor is expressed (Non-Patent Document 5). The reproducibility among multiple subjects is also high enough to enable stable olfactory presentation.

[0006] In addition, as olfactory electrical stimulation using odorant substances, it has been reported that by performing non-invasive electrical stimulation near the wrist, it acts on the vagus nerve network via the median nerve, and an inhibitory effect on the presented odor intensity is observed (Non-Patent Document 6).

Prior Art Documents

[0007]

Patent Document 1

Non-licensed literature

[0008] [Non-licensed document 1] Gogi Kumar, Csaba Juh´asz, Sandeep Sood, Eishi Asano, “Olfactory hallucinations elicited by electrical stimulation via subdural electrodes: effects of direct stimulation of olfactory bulb and tract”, Epilepsy Behav. 2012 Jun;24(2):264-8. [Non-licensed document 2] Laure Mazzola, Jean-Pierre Royet, H'el'ene Catenoix, Alexandra Montavont, Jean Isnard, Fran'cois Maugui'ere, "Gustatory and olfactory responses to stimulation of the human insula", Ann Neurol. 2017 Sep;82(3):360-370. [Non-licensed document 3] Eric H. Holbrook MD, Sidharth V. Puram MD, PhD, Reiner B. See MD, Aaron G. Tripp BS, CNIM, Dinesh G. Nair MD, M. Tech, PhD 2019 Pages125-2

Outdoor Tools 4

Direct Environment 5

Outdoor Configuration6

[0009] However, Non-Patent Document 5 does not report on effects related to odor intensity, such as activation or inhibition. Furthermore, Non-Patent Document 6 confirms the inhibitory effect after 10 minutes of electrical stimulation, which cannot be considered an immediate phenomenon.

[0010] One aspect of the present invention aims to realize an olfactory adjustment device, etc., capable of instantly changing odor intensity. [Means for solving the problem]

[0011] To solve the above problems, an olfactory adjustment device according to embodiment 1 of the present invention comprises a first electrode and a second electrode, which are arranged such that the nasal cavity is located between the first electrode and the second electrode, and a current supply unit that changes the odor intensity of the olfactory sense by supplying a current between the first electrode and the second electrode.

[0012] With the above configuration, by supplying current from the current supply unit between the first electrode and the second electrode, it becomes possible to instantly change the odor intensity.

[0013] In the olfactory adjustment device according to embodiment 2 of the present invention, in embodiment 1, the current supply unit may supply a direct current between the first electrode and the second electrode.

[0014] In the olfactory adjustment device according to embodiment 3 of the present invention, in embodiment 1, the current supply unit may supply a continuous rectangular wave DC current between the first electrode and the second electrode.

[0015] In the olfactory adjustment device according to embodiment 4 of the present invention, in embodiment 1, the current supply unit may supply an alternating current between the first electrode and the second electrode.

[0016] In the olfactory adjustment device according to embodiment 5 of the present invention, in embodiment 1, 3, or 4, the current supply unit may change the odor intensity of the olfactory sense by changing the duty cycle of the current.

[0017] In the olfactory adjustment device according to embodiment 6 of the present invention, in any of embodiments 1 to 5, the current supply unit may switch between enhancing and suppressing the odor intensity of the olfactory sense by changing the polarity of the current.

[0018] In the olfactory adjustment device according to embodiment 7 of the present invention, in any of embodiments 1 to 6, the current supply unit may change the magnitude of the effect of enhancing or suppressing the odor intensity by changing the magnitude of the current without changing the polarity of the current.

[0019] In the olfactory regulation device according to aspect 8 of the present invention, in any one of aspects 1 to 7, the first electrode may be disposed on the skin above the nose of the human body, and the second electrode may be disposed on the skin below the nose of the human body.

[0020] In the olfactory regulation device according to aspect 9 of the present invention, in any one of aspects 1 to 7, the first electrode may be disposed on the front skin of the human body, and the second electrode may be disposed on the back skin of the human body.

[0021] In the olfactory regulation device according to aspect 10 of the present invention, in any one of aspects 1 to 7, the first electrode may be disposed on the skin to the left of the nose of the human body, and the second electrode may be disposed on the skin to the right of the nose of the human body.

[0022] The olfactory display according to aspect 11 of the present invention includes the olfactory regulation device according to any one of aspects 1 to 10 and a release unit that releases an odorant. After the release unit releases the odorant, the current supply unit changes the current to change the odor intensity caused by the odorant released from the release unit.

[0023] According to the above configuration, by quickly suppressing the odor intensity of the smell, it becomes possible to quickly eliminate the remaining odor.

[0024] The olfactory display according to aspect 12 of the present invention further includes a taste regulation device in aspect 11. The taste regulation device includes the third electrode and the fourth electrode disposed such that the tongue is located between the third electrode and the fourth electrode, and a current supply unit that supplies a current between the third electrode and the fourth electrode to change the taste intensity of the taste.

[0025] According to the above configuration, it is possible to separately present the effect of changing the taste intensity of the taste by the taste regulation device and the effect of changing the odor intensity of the smell by the olfactory regulation device 20.

[0026] An olfactory adjustment method according to embodiment 13 of the present invention includes an arrangement step of arranging the first electrode and the second electrode such that the nasal cavity is located between the first electrode and the second electrode, and a current supply step of changing the odor intensity of the olfactory sense by supplying a current between the first electrode and the second electrode. [Effects of the Invention]

[0027] According to one aspect of the present invention, it is possible to realize an olfactory adjustment device that can instantly change the odor intensity. [Brief explanation of the drawing]

[0028] [Figure 1] This figure shows an example of an experimental apparatus for olfactory electrical stimulation, including an olfactory adjustment device according to an embodiment of the present invention, along with an enlarged view of its main components. [Figure 2] This figure shows the relationship between the subject's actions (breathing, button pressing, and responding) and the waveform of the electrical current supplied to the subject in an experiment conducted using the experimental apparatus shown in Figure 1. [Figure 3] This figure shows an example of the arrangement of the first and second electrodes of the olfactory adjustment device shown in Figure 1. [Figure 4] This figure shows an example of the current waveform flowing between the first electrode and the second electrode from the current supply unit of the olfactory adjustment device shown in Figure 1. [Figure 5] This figure shows an example of the current waveform flowing between the first electrode and the second electrode from the current supply unit of the olfactory adjustment device shown in Figure 1. [Figure 6] This block diagram shows the configuration of an olfactory display equipped with an olfactory adjustment device as shown in Figure 1. [Figure 7] This diagram shows an example of a taste adjustment device, along with a magnified view of its main components. [Modes for carrying out the invention]

[0029] As described in the background technology section, methods using electrical stimulation for sensory presentation have been studied before, and the senses targeted include touch, vestibular sensation, and taste. Among these, there is a classification called chemical stimulation, and there are similarities in the perceptual mechanisms of taste and smell.

[0030] The inventors of this application focused on GTS, one of the taste electrical stimulation methods reported in Non-Patent Document 7. GTS is a technique that changes (modulates) the taste intensity of an aqueous solution containing electrolytic taste substances by transcutaneous electrical stimulation. The mechanism of action of this technique is based on the electrophoretic phenomenon, and it makes possible that local changes in the concentration of electrolytes in the aqueous solution bring about a change in the perception of taste intensity in humans.

[0031] Let's consider the mechanism of olfaction. Odor perception occurs when odor molecules dissolve in olfactory mucus and attach to receptors on olfactory cilia, causing a change in membrane potential, which is then transmitted to the brain as nerve impulse signals. More specifically, odor molecules attached to receptors on olfactory cilia in the olfactory epithelium change the membrane potential of olfactory cells, which are then converted into nerve impulses by olfactory nerves passing through tiny pores in the bone and transmitted to the olfactory bulb (part of the cerebral cortex). Olfactory mucus, in which odor molecules are dissolved, can be likened to an aqueous solution in which electrolytes are dissolved.

[0032] Therefore, the inventors of this invention hypothesized that, like GTS, it would be possible to manipulate electrolytes through electrophoresis, and investigated whether it was possible to change the odor intensity. As a result, the inventors of this invention discovered an olfactory electrostimulation method that enables immediate suppression and enhancement of odor.

[0033] The method discovered by the present inventors allows for immediate suppression and enhancement of odors in electrolytic odor substances. This phenomenon can be used to address the problem of suppressing odor persistence, which is a challenge in olfactory displays. Furthermore, it is possible to adjust the odor intensity in the sense of smell without increasing or decreasing the amount of odor substance, thereby strengthening or weakening the odor.

[0034] (Explanation of the experiment conducted based on the hypothesis) First, we will explain the results of our investigation into whether it is possible to change the odor intensity based on a hypothesis. Figure 1 is a diagram showing an example of an experimental apparatus for olfactory electrical stimulation, including an olfactory adjustment device 20 according to an embodiment of the present invention, along with an enlarged view of the main parts. The experimental apparatus includes the olfactory adjustment device 20. The olfactory adjustment device 20 includes a first electrode 21 and a second electrode 22, and a current supply unit 23 that supplies current between the first electrode 21 and the second electrode 22.

[0035] The current supply unit 23 can supply DC current, AC current, continuous square wave DC current, continuous square wave AC current, etc., as stimulus signals. The current supply unit 23 can supply stimulus signals of various waveforms by controlling (changing) the polarity of the current, the magnitude (amplitude) of the current, the duty cycle, the frequency, and / or the phase.

[0036] Either the first electrode 21 or the second electrode 22 is connected to the positive terminal of the current supply unit 23 via a conductor, and the other of the first electrode 21 or the second electrode 22 is connected to the negative terminal of the current supply unit 23 via a conductor.

[0037] In experiments 1 to 3 described below, the first electrode 21 is connected to the positive terminal and functions as the anode electrode, and the second electrode 22 is connected to the negative terminal and functions as the negative electrode. In experiments 1 to 3, the second electrode 22, which is the cathode, is placed in the philtrum area below the nose of the subject, and the first electrode 21, which is the anode, is placed on the subject's forehead.

[0038] (1) Experiment 1 <Exploratory experiment on the effect of changing odor intensity> (1-1) Experimental Objectives This study investigates the presence and reproducibility of an effect (odor intensity change effect) that occurs when the value of the electrical current applied during transcutaneous electrical stimulation near the nose is changed while inhaling non-electrolyte and electrolyte odor substances.

[0039] (1-2) Experiment Content Four types of odor substances were used: 6 wt% acetic acid aqueous solution, 2.5 wt% ethanol, 0.4 wt% ammonia aqueous solution, and purified water. Nine different currents were supplied from the current supply unit 23, transitioning from 1.0 mA, -1.0 mA, and 0 mA to either 1.0 mA, -1.0 mA, or 0 mA. Note that supplying a current of 1 mA means supplying a 1 mA current from the first anode electrode 21 to the second cathode electrode 22. Figure 2 shows the relationship between the subject's actions (breathing, button pressing, and answering) and the waveform of the current supplied to the subject in the experiment conducted with the experimental apparatus shown in Figure 1.

[0040] A series of initial current values ​​containing nine different current transition conditions to be measured was prepared in advance, and the current values ​​were applied to one subject in the order of this series. As shown in Figure 2, the current values ​​were transitioned at the timing of the subject's button press. The timing of the button press was set to occur during inhalation and to allow a certain number of seconds before and after the current transition in order to observe the effect of changes in odor intensity in the sense of smell.

[0041] After the current value transition, participants were asked to respond using a two-option forced choice method whether or not they perceived an effect of changing odor intensity. After each of the nine current value transitions corresponding to the nine conditions mentioned above, an interval of 1 to 2 minutes was ensured, and at least three trials were conducted.

[0042] Subsequently, if any conditions were found to exhibit a high probability of change, a new current value series with refined transition conditions was created and presented several times. As a result, the condition with the highest reproducibility was adopted as the experimental condition for Experiment 2.

[0043] (1-3) Experimental results The results of presenting the initial current value series: 0→-1→-1→1→1→0→1→-1→0 are shown in Table 1.

[0044] [Table 1] As shown in Table 1, measurements were taken in the initial current value series three times with purified water and four times with 2.5 wt% ethanol. However, no significant change was observed in any of the measurements, so Experiment 2 was not performed.

[0045] As shown in Table 1, measurements were performed three times with the initial current value series using a 6 wt% acetic acid aqueous solution. The results showed a significant change in the transition conditions {1→-1,-1→0,-1→1}. Therefore, measurements were performed twice with a second current value series that focused on these transition conditions: -1→1→-1→0→-1→1→-1→0→-1→1. The results are shown in Table 2.

[0046] [Table 2] Table 2 shows the results of an experiment that collected only the conditions with high probability of change in Table 1. When the results of Table 1 and Table 2 are combined, the transition condition with the highest probability of change was -1→1, at 77.8%.

[0047] As shown in Table 1, measurements were performed three times in the initial current value series for a 0.4 wt% ammonia aqueous solution. The results showed a significant change in the transition conditions {0→1, 0→-1, 1→0, 1→-1, -1→0, -1→1}. Therefore, measurements were performed twice in a second current value series that focused on these transition conditions: -1→1→-1→0→1→-1→1→0→-1→0→1. The results are shown in Table 3.

[0048] [Table 3] Table 3 shows the results of an experiment that collected only the conditions with high probability of change in Table 1. When the results of Table 1 and Table 3 are combined, the transition condition with the highest probability of change was 0→1, at 85.7%.

[0049] (2) Experiment 2 <Exploratory experiment to determine the concentration range in which odor intensity changes occur> (2-1) Experimental Objectives This experiment verifies at what concentration range of solutions containing each odor substance the odor intensity change effect due to current value transitions, which was revealed in Experiment 1, occurs.

[0050] (2-2) Experiment Content As odorants, 0.125-10 wt% acetic acid aqueous solutions and 0.00625-0.8 wt% ammonia aqueous solutions were used. When electrical stimulation was performed using the acetic acid aqueous solution, a pulsed current transition from -1.0 mA to 1.0 mA, as obtained in Experiment 1, was generated. When electrical stimulation was performed using the ammonia aqueous solution, a pulsed current transition from 0.0 mA to 1.0 mA, as obtained in Experiment 1, was generated.

[0051] For both acetic acid and ammonia solutions, a series of nine different concentrations was prepared, and the up-and-down method was used on one subject. While the subject inhaled an odor substance at a certain concentration within the series, an electric current was applied. As in Experiment 1, the current value transition was triggered by the subject pressing a button. The timing of the button press was carefully considered to allow sufficient time for both the inhalation and the transition of the current to observe the effect of changes in odor intensity on the sense of smell.

[0052] After the current value transition, participants were asked to respond using a two-option forced-choice method whether they felt an effect of changing odor intensity. The transition between the ascending and descending series occurred when the participant's response changed from "felt an effect" to "did not feel an effect." The ascending / descending method ended after three series transitions, and the concentration midway between the inflection points was adopted as the condition for Experiment 3.

[0053] (2-3) Experimental results Table 4 shows the changes in the up-and-down method in aqueous acetic acid solution. As shown in Table 4, the effect of the change was only observed at an acetic acid concentration of 6 wt%.

[0054] [Table 4] Table 5 shows the changes in the up-and-down method for aqueous ammonia solutions. As shown in Table 5, the effect of the change was confirmed at ammonia concentrations of 0.4 wt% and 0.2 wt%.

[0055] [Table 5] (3) Experiment 3 <Experiment to confirm the direction of change in odor intensity> (3-1) Experimental Objectives We will investigate whether the odor intensity change effect shifted to suppression or enhancement under the current value transition conditions revealed in Experiment 1 and the concentration conditions revealed in Experiment 2.

[0056] (3-2) Experiment Content A 6 wt% aqueous solution of acetic acid and a 0.2 wt% aqueous solution of ammonia were used as odorants. When electrical stimulation was performed using the aqueous solution of acetic acid, a pulsed current transition from -1.0 mA to 1.0 mA, as obtained in Experiment 1, was generated. When electrical stimulation was performed using the aqueous solution of ammonia, a pulsed current transition from 0.0 mA to 1.0 mA, as obtained in Experiment 1, was generated.

[0057] Experiment 3 was conducted on one subject. As in Experiments 1 and 2, the current value transition was triggered by the subject pressing a button. The timing of the button press was set to occur during inhalation and to allow a certain number of seconds before and after the current transition in order to observe the effect of changes in odor intensity in the sense of smell.

[0058] After the current value transition, participants were asked to respond to their impression of odor intensity using a three-option forced-choice method: "suppressed," "enhanced," or "no change." First, three trials were conducted for each condition, and then an additional 10 trials were performed on a separate day.

[0059] (3-3) Experimental Results In a 6 wt% aqueous acetic acid solution, the results were "suppressed" in 9 out of 13 trials, "no change" in 3 trials, and "enhanced" in 1 trial. In a 0.2 wt% aqueous ammonia solution, the results were "enhanced" in 10 out of 13 trials and "no change" in 3 trials.

[0060] (4) Discussion In Experiment 1, the conditions under which changes in odor intensity occur due to electric current stimulation were investigated for odorless water and aqueous solutions of non-electrolyte ethanol, electrolyte acetic acid, and ammonia. For water, responses indicating no change in odor intensity were obtained in most conditions, suggesting that no odor presentation occurred due to electrical stimulation. Furthermore, since the responses indicating no change in odor intensity for non-electrolyte ethanol were higher for aqueous solutions of electrolytes such as acetic acid and ammonia, it is thought that the change in odor intensity due to electric current acts on the odor intensity exhibited by electrolytes. This is thought to be similar to the oral ion electrophoresis hypothesis in GTS, where ions in nasal mucus are generated by electrophoresis due to the potential gradient.

[0061] In Experiment 3, we investigated whether the change in odor intensity was suppression or enhancement under experimental conditions where the probability of a change in odor intensity was high in previous experiments. In the case of the 6 wt% acetic acid aqueous solution, under the condition of current value transition from -1.0 mA to 1.0 mA, the most frequent response was suppression, suggesting that the change in odor intensity was suppressive. On the other hand, in the case of the 0.2 wt% ammonia aqueous solution, under the condition of current value transition from 0.0 mA to 1.0 mA, the most frequent response was enhancement, suggesting that the change in odor intensity was enhancement.

[0062] Both current value transition conditions involve an increase in the positive direction of the current value, but the perceived direction of change is reversed. In this study, we hypothesized that a phenomenon in phase with GTS could also be expected in olfactory electrical stimulation and conducted experiments. Considering that acetic acid solution is acidic and ammonia solution is basic, the perceived direction of change being reversed is not inconsistent with the conclusion drawn from the hypothesis. In other words, it is possible to manipulate the electrolytes dissolved in olfactory mucus by electrical stimulation, and it is thought that it is also possible to manipulate the olfactory impression by manipulating these electrolytes.

[0063] (Olfactory regulation device) Hereinafter, an olfactory adjustment device 20 according to an embodiment of the present invention will be described in detail. As mentioned above, the olfactory adjustment device 20 shown in Figure 1 comprises a first electrode 21 and a second electrode 22, and a current supply unit 23 that supplies current between the first electrode 21 and the second electrode 22.

[0064] <First electrode and second electrode> As shown in Figure 1, the first electrode 21 and the second electrode 22 are positioned such that the nasal cavity is located between the first electrode 21 and the second electrode 22. Specifically, the first electrode 21 and the second electrode 22 are positioned (attached) to the user (subject) 11 such that the nasal cavity 12 is included in the current path R formed between the first electrode 21 and the second electrode 22. With the first electrode 21 and the second electrode 22 positioned, the user's nasal cavity 12 is sandwiched between the first electrode 21 and the second electrode 22. However, it is not that the nasal cavity is sandwiched between the first electrode 21 and the second electrode 22 in three dimensions; it is sufficient that the current flowing between the first electrode 21 and the second electrode 22 passes through the nasal cavity 12.

[0065] More precisely, it is sufficient that the mucous membrane of the olfactory epithelium of the nasal cavity 12 is included in the current path R. Furthermore, more preferably, the current flowing between the first electrode 21 and the second electrode 22 passes through the olfactory bulb 14 through the fine pores 13a formed in the bone 13.

[0066] Figure 3 shows an example of the arrangement of the first electrode 21 and the second electrode 22 of the olfactory adjustment device 20 shown in Figure 1. As shown in Figure #301 of Figure 3, the first electrode 21 may be placed on the skin above the nose where the nasal cavity 12 of the user (human body) 11 is located, and the second electrode 22 may be placed on the skin below the nose of the user 11.

[0067] The upper part of user 11 above the nose is the part of the head including the face above the nose, and includes the forehead, temples, crown of the head, back of the head, etc. The lower part of user 11 below the nose is the part of the head including the face below the nose and the neck, and includes the area below the nose (philtrum), chin, etc. The current flowing between the first electrode 21 and the second electrode 22, which are positioned above the nose and below the nose, can be arranged in any combination of positions that pass through the nasal cavity 12.

[0068] As shown in Figure 3, #302, the first electrode 21 may be placed on the front of the user 11's skin, and the second electrode 22 on the back of the user 11's skin. The front of the user 11 is the front of the head and neck, including the face, and includes the forehead, temples, philtrum, chin, and front of the neck. The back of the user 11 is the back of the head and neck, including the back of the head and back of the neck. The combination of placement positions is such that the current flowing between the first electrode 21 and the second electrode 22 placed on the front and back passes through the nasal cavity 12.

[0069] As shown in Figure 3, #303, the first electrode 21 may be placed on the skin to the left of the user 11's nose, and the second electrode 22 may be placed on the skin to the right of the user 11's nose. The area to the left of the user 11's nose is the area to the left of the nose on the head, including the face, and includes the left cheek, left ear, the area around the left ear, the left temple, etc. The area to the right of the user 11's nose is the area to the right of the nose on the head, including the face, and includes the right cheek, right ear, the area around the right ear, the right temple, etc. The combination of placement positions is such that the current flowing between the first electrode 21 and the second electrode 22 placed on the left and right sides passes through the nasal cavity 12.

[0070] <Current supply section 23> The current supply unit 23 changes the odor intensity of the olfactory sense by passing an electric current between the first electrode 21 and the second electrode 22.

[0071] As described above, the current supply unit 23 supplies a DC current, an AC current, a continuous square wave DC current, a continuous square wave AC current, etc., as a stimulus signal between the first electrode 21 and the second electrode 22.

[0072] The current supply unit 23 can supply currents of various waveforms by controlling (changing) the polarity of the current, the magnitude of the current (amplitude of the waveform), the duty cycle, the frequency and / or the phase of the supplied current.

[0073] The current supply unit 23 may switch between enhancing and suppressing the olfactory odor intensity by changing the polarity of the current it supplies. The current supply unit 23 may also change the olfactory odor intensity by changing the duty cycle of the current it supplies. Alternatively, the current supply unit 23 may change the magnitude of the effect of enhancing or suppressing the olfactory odor intensity by changing the magnitude of the current without changing the polarity of the current it supplies.

[0074] The polarity and current value of the current supplied by the current supply unit 23 depend on the odor substance whose odor intensity is altered in the sense of smell. The target odor substance is an electrolytic odor substance. The polarity, current value, waveform, etc. of the current supplied by the current supply unit 23 are determined by the type of odor substance, the concentration of the odor substance, the polarity (acidic / basic) when the odor substance is electrolytically treated, and whether the odor intensity is enhanced or suppressed.

[0075] Figure 4 shows an example of the current waveform flowing between the first electrode 21 and the second electrode 22 from the current supply unit 23 of the olfactory adjustment device 20 shown in Figure 1.

[0076] The current waveform #401 in Figure 4 is a positive single-wave square wave, representing a waveform that flows a predetermined positive current for a predetermined time. With the current waveform #401, if the predetermined positive current value has an odor intensity enhancing effect, the odor intensity will remain enhanced while this current is flowing. Conversely, if the predetermined positive current value has an odor intensity suppressing effect, the odor will remain suppressed while this current is flowing.

[0077] For example, a second electrode 22 connected to the cathode terminal of the current supply unit 23 is placed below the nose of the user 11, and a first electrode 21 connected to the anode terminal of the current supply unit 23 is placed on the user's forehead. Then, a current with the current waveform of #401 is passed between the first electrode 21 and the second electrode 22 with an amplitude of 1.0mA.

[0078] When the odor substance is a 0.2 wt% ammonia aqueous solution, an odor enhancement effect is obtained during the period when a 1.0 mA DC current is flowing, and no enhancement effect is obtained during the period when no current is supplied (zero current, no power flow). The odor intensity perceived by the olfactory sensor is sharply enhanced at the rising edge of the waveform when the supply of 1.0 mA DC current begins, and the enhancement effect disappears at the falling edge of the waveform when the supply of 1.0 mA DC current stops. In this way, the odor intensity can be changed instantly using the olfactory adjustment device 20.

[0079] The current waveform #402 in Figure 4 is a negative single-wave square wave, representing a waveform that flows a predetermined negative current for a predetermined time. With the current waveform #402, if the predetermined negative current value has an odor intensity enhancing effect, the odor intensity will remain enhanced while this current is flowing. Conversely, if the predetermined negative current value has an odor intensity suppressing effect, the odor will remain suppressed while this current is flowing.

[0080] Although not shown in the diagram, it may also be a single-pulse rectangular wave that directly switches from a negative DC current to a positive DC current, or from a positive DC current to a negative DC current, and delivers a predetermined positive or negative current for a predetermined time.

[0081] For example, a second electrode 22 connected to the cathode terminal of the current supply unit 23 is placed below the nose of the user 11, and a first electrode 21 connected to the anode terminal of the current supply unit 23 is placed on the user's forehead. Then, after supplying a DC current of -1.0 mA, a DC current of 1.0 mA is passed between the first electrode 21 and the second electrode 22 for a predetermined time.

[0082] When the odor substance is a 6 wt% aqueous acetic acid solution, an odor suppression effect is obtained during the period when a 1.0 mA DC current is flowing, and no suppression effect is obtained during the period when a -1 mA current is supplied. The olfactory odor intensity decreases sharply (suppression) at the rising edge of the waveform when the current value switches from -1.0 mA to 1.0 mA, and the suppression effect disappears at the falling edge of the waveform when the current value switches from 1.0 mA to -1.0 mA. In this way, the odor intensity can be changed instantly using the olfactory adjustment device 20.

[0083] The current waveform of #403 in Figure 4 is a positive single-pulse square wave, with the supplied positive current value set in multiple stages (two stages in the figure). By using such a waveform, if the change in odor intensity is an enhancement effect, the odor intensity can be enhanced through multiple stages. Conversely, if the change in odor intensity is an inhibitory effect, the odor intensity can be suppressed through multiple stages.

[0084] Furthermore, although not shown in the diagram, the supplied negative current value may be reduced in multiple stages. Also, in the current waveform described above, where the DC current switches directly from negative DC current to positive DC current, and from positive DC current to negative DC current, the current value may be increased or decreased in multiple stages.

[0085] The current waveform #404 in Figure 4 is a positive unipolar continuous square wave, a waveform that carries a predetermined positive current at a predetermined period. In the case of the current waveform #404, whether it suppresses or enhances the current depends on the frequency and the length of the period of zero current (no current) between consecutive square waves. Although not shown in the figure, the same applies to negative unipolar continuous square waves.

[0086] When the frequency of a unipolar continuous square wave falls below 10Hz, the human sense of smell perceives a change in odor. This results in discontinuity of perception, similar to intermittently playing the single square wave #401, leading to repeated suppression and enhancement.

[0087] On the other hand, when the frequency of the monopolar continuous square wave exceeds 10 Hz, the human sense of smell has difficulty perceiving the change in odor. Therefore, when the frequency is between 10 and 100 Hz, the odor change is enhanced overall. It is noteworthy that when the frequency is between 10 and 100 Hz, even if a given positive current value has an inhibitory effect on odor intensity, it results in enhancement. This is thought to be because, as a result of repeated inhibition and presentation, the sense of smell becomes more strongly perceived as changing the odor, leading to enhancement. When the frequency of the monopolar continuous square wave exceeds 100 Hz, the movement of electrolytes in odor substances is restricted, resulting in no perceived change or inhibition of the change.

[0088] Furthermore, in the case of a unipolar continuous square wave, in addition to frequency, if the period of zero current is sufficiently short, approximately 100 ms, the odor change effect will continue. On the other hand, if the period of zero current exceeds approximately 100 ms, an inhibitory or enhancing effect due to the positive current value occurs, followed by a return to the perceptual state when no current stimulation is received, and the effect will occur again when current is applied next.

[0089] The current waveform for #405 in Figure 4 is a positive unipolar continuous square wave with the supplied positive current value set in multiple stages (two stages in the figure). Whether it suppresses or enhances the current depends on the frequency and the length of the zero-current period. Although not shown in the figure, the same applies to negative unipolar continuous square waves.

[0090] The current waveform of #406 in Figure 4 is a positive DC sine wave that has been phase-modulated or frequency-modulated. In this case, modulating the frequency or phase results in either suppression or enhancement.

[0091] Figure 5 shows an example of the current waveform flowing between the first electrode 21 and the second electrode 22 from the current supply unit 23 of the olfactory adjustment device 20 shown in Figure 1. Figure 5 shows an example of the current waveform when AC current is supplied.

[0092] The current waveform #501 in Figure 5 is an AC square wave, which alternates between a predetermined positive current and a predetermined negative current at a predetermined period. In the case of the current waveform #501, similar to the current waveform #404 in Figure 4, whether it suppresses or enhances the current depends on the frequency and the ratio of positive to negative intervals in the current value between consecutive square waves.

[0093] The current waveform #502 in Figure 5 is an AC square wave with multiple positive and negative current values ​​set in stages (two stages on the positive side and three stages on the negative side in the figure). By using such a waveform, similar to the current waveform #403 in Figure 4, if the change in odor intensity is an enhancement effect, the odor intensity can be enhanced through multiple stages. Conversely, if the change in odor intensity is an inhibitory effect, the odor intensity can be suppressed through multiple stages.

[0094] The current waveform #503 in Figure 5 is an AC square wave with positive and negative duty cycles set, respectively. In other words, if the positive current flow time is T1, the time of no current flow immediately after the positive current is T2, the negative current flow time is T3, and the time of no current flow immediately after the negative current is T4, then this is a current waveform that changes the ratio of T1:T2:T3:T4. In this case as well, the effect of the change in odor intensity during the period of zero current is determined by the time interval until the next current flows. If the period of zero current is short enough that it is difficult to perceive the switch in odor change, the odor change effect continues. On the other hand, if the period of zero current is long enough that the switch in odor change can be perceived, the effect of suppressing or enhancing the positive current occurs, then the perception returns to the state when there was no current stimulation, and the effect occurs again when the next current is applied.

[0095] The current waveform of #504 in Figure 5 is obtained by applying phase modulation or frequency modulation to an AC sine wave. In this case, modulating the frequency or phase results in either suppression or enhancement.

[0096] Note that the current waveforms shown in Figures 4 and 5 are merely examples; for example, waveforms could be generated by adding or subtracting the waveforms from #401 to #406 in Figure 4 and #501 to #504 in Figure 5.

[0097] (Methods of olfactory regulation) As shown in Figures 1 and 3, the olfactory adjustment method according to an embodiment of the present invention includes an arrangement step of arranging the first electrode 21 and the second electrode 22 such that the nasal cavity 12 is located between the first electrode 21 and the second electrode 22, and a current supply step of changing the odor intensity of the olfactory sense by supplying a current between the first electrode 21 and the second electrode 22.

[0098] (Olfactory display) The following describes in detail an olfactory display 30 according to an embodiment of the present invention. Figure 6 is a block diagram showing the configuration of an olfactory display 30 equipped with the olfactory adjustment device 20 shown in Figure 1. As shown in Figure 6, the olfactory display 30 comprises an olfactory adjustment device 20, a display unit 31, an emission unit 32 that emits odor substances, and a control unit 33 that controls these. The current supply unit 23 (see Figure 1) of the olfactory adjustment device 20 changes the odor intensity caused by the odor substances emitted from the emission unit 32 by changing the current supplied after the emission unit 32 has emitted odor substances. Note that the display unit 31 is not essential in the olfactory display 30.

[0099] By rapidly suppressing the intensity of odors perceived by the sense of smell, any remaining odors can be quickly eliminated. This allows, for example, odor substances sprayed for a performance to be quickly removed as the scene changes.

[0100] (Other application examples) The olfactory modulator 20 can be used not only with the olfactory display 30 but also with the following technologies. For example, it can be used in combination with GTS, one of the taste electrical stimulation methods reported in the aforementioned Non-Patent Document 7, and is expected to have applications in food-related fields, including the eating experience.

[0101] For example, Patent Document 1 discloses a taste electrical stimulator using a GTS. Such a taste electrical stimulator can also be combined with an olfactory modifier 20 as a taste modifier to form a taste-olfactory modifier system.

[0102] Figure 7 shows an example of a taste adjustment device 40, along with an enlarged view of its main components. As shown in Figure 7, the taste adjustment device 40 comprises a third electrode 41 and a fourth electrode 42, and a current supply unit 43 that supplies current between the third electrode 41 and the fourth electrode 42.

[0103] The third electrode 41 and the fourth electrode 42 are positioned on the user 11 such that the tongue 16 is included in the current path R1 formed between the third electrode 41 and the fourth electrode 42. In Figure 7, the third electrode 41 and the fourth electrode 42 are positioned behind the mandible and neck.

[0104] In the taste-olfactory adjustment system, the effect of changing the taste intensity due to the GTS effect and the effect of changing the odor intensity due to the olfactory adjustment device 20 can be presented separately.

[0105] Although not shown in the diagram, in a taste-olfactory regulating system, it is also possible to share one of the electrodes between the pair of electrodes of the olfactory regulating device 20, namely the first electrode 21 and the second electrode 22, and the pair of electrodes of the taste-regulating device 40, namely the third electrode 41 and the fourth electrode 42, resulting in a total of three electrodes. For example, a taste-olfactory regulating system may comprise a first electrode 21, a second electrode 22, and a third electrode 41. The electrodes may be arranged such that the current path R (see Figure 1) formed between the first electrode 21 and the second electrode 22 includes the nasal cavity 12, and the current path R1 formed between the second electrode 22 and the third electrode 41 includes the tongue 16. For example, the first electrode 21 may be placed on the forehead, the second electrode 22 on the back of the neck, and the third electrode 41 on the lower jaw.

[0106] Furthermore, although it is specifically designed to suppress odor intensity, using the olfactory adjustment device 20 in environments with unpleasant odors makes it possible to suppress the odor and improve the working environment.

[0107] For those specifically focused on enhancing odor intensity, the olfactory adjustment device 20 can be used to detect the presence of harmful odor substances even in very small amounts, thus ensuring safety. [Explanation of Symbols]

[0108] 11 User 12 Nasal cavity 13 bones 14 Olfactory bulb 20 Olfactory adjustment device 21 1st electrode 22 2nd electrode 23 Current supply section 30 Olfactory Display 31 Display section 32 Emission part 33 Control Unit 40 Taste adjustment device 41 3rd electrode 42 4th electrode 43 Current supply section

Claims

1. The first electrode and the second electrode are positioned such that the nasal cavity is located between the first electrode and the second electrode, An olfactory adjustment device comprising: a current supply unit that changes the odor intensity of the sense of smell by supplying a current between the first electrode and the second electrode.

2. The olfactory adjustment device according to claim 1, wherein the current supply unit supplies a direct current between the first electrode and the second electrode.

3. The olfactory adjustment device according to claim 2, wherein the current supply unit supplies a continuous rectangular wave DC current between the first electrode and the second electrode.

4. The olfactory adjustment device according to claim 1, wherein the current supply unit supplies alternating current between the first electrode and the second electrode.

5. The olfactory adjustment device according to claim 1, wherein the current supply unit changes the odor intensity by changing the duty cycle of the current.

6. The olfactory adjustment device according to claim 1, wherein the current supply unit switches between enhancing and suppressing the odor intensity by changing the polarity of the current.

7. The olfactory adjustment device according to claim 1, wherein the current supply unit changes the magnitude of the effect of enhancing or suppressing the odor intensity of the olfactory sense by changing the magnitude of the current without changing the polarity of the current.

8. The first electrode is placed on the skin above the nose of the human body. The olfactory regulating device according to claim 1, wherein the second electrode is positioned on the skin of the human body below the nose.

9. The first electrode is placed on the skin on the front side of the human body. The olfactory adjustment device according to claim 1, wherein the second electrode is placed on the skin on the posterior side of the human body.

10. The first electrode is placed on the skin to the left of the nose of the human body. The olfactory regulating device according to claim 1, wherein the second electrode is positioned on the skin to the right of the nose of the human body.

11. An olfactory adjustment device according to any one of claims 1 to 10, It comprises a discharge section that releases odor-causing substances, An olfactory display wherein, after the discharge unit has discharged the odor substance, the current supply unit changes the current to change the odor intensity caused by the odor substance discharged from the discharge unit.

12. The olfactory adjustment device according to claim 1, Equipped with a taste adjustment device, The aforementioned taste adjustment device is The third electrode and the fourth electrode are positioned such that the tongue is located between the third electrode and the fourth electrode, A taste and smell adjustment system comprising: a current supply unit that changes the taste intensity by supplying current between the third electrode and the fourth electrode.

13. The olfactory adjustment device according to claim 1, Equipped with a taste adjustment device, The aforementioned taste adjustment device is The third electrode is positioned such that the tongue is located between the third electrode and the second electrode, A taste and smell adjustment system comprising: a current supply unit that changes the taste intensity by supplying current between the third electrode and the second electrode.

14. The procedure involves positioning the first electrode and the second electrode such that the nasal cavity is located between the first electrode and the second electrode, A method for regulating olfaction, comprising a current supply step of changing the odor intensity of the sense of smell by supplying a current between the first electrode and the second electrode.

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