JP7233196B2 - Odor Presentation System, Control Program and Odor Presentation Method - Google Patents

Description

TECHNICAL FIELD The present invention relates to an odor presentation system, a control program, and an odor presentation method, and more particularly to an odor presentation system, a control program, and an odor presentation method that present an odor in time with the breathing of a subject.

The background art of this invention is disclosed in Japanese Patent Application Laid-Open No. 2002-200012. In the inspiratory reaction measuring device of Patent Document 1, a thermistor is attached as a sensor to the entrance of the subject's nasal cavity, and the respiratory state of the subject is detected by the sensor based on the temperature change caused by the inflow and outflow of the subject's breath. Correspondingly, an odor stimulus is given to the subject.

Japanese Patent Laid-Open No. 63-79636

However, the background art olfactory response measurement apparatus only provides odor stimulation to the subject in response to the inhalation period, and synchronizes with the imaging process of the MRI apparatus for measuring the brain activity of the subject given the odor stimulation. not envisioned so far. Therefore, it may not be possible to accurately capture the rising portion of the fMRI signal when the odor stimulus is presented.

SUMMARY OF THE INVENTION Therefore, a primary object of the present invention is to provide a novel odor presenting system, control program, and odor presenting method.

Another object of the present invention is to provide an odor presenting system, a control program, and an odor presenting method that can reliably detect the rise of an fMRI signal due to the application of an odor stimulus.

A first invention is an odor presenting system for presenting an odor to a subject whose brain activity is measured by an MRI apparatus, wherein a synchronous trigger signal indicating a first start timing of imaging processing for the entire head of the subject from the MRI apparatus. synchronous trigger detection means for detecting the respiratory trigger detection means for detecting a respiratory trigger signal indicating the second start timing of inspiration of the subject; The odor presenting system includes odor presenting means for presenting a predetermined odor to a subject when .

A second invention is according to the first invention, further comprising filling means for filling gas of the predetermined odor into the odor release portion prior to presentation of the predetermined odor, wherein the breathing trigger detection means comprises: A respiration trigger signal is detected in response to filling of the odor release portion with gas of a predetermined odor by the filling means.

A third invention is according to the first or second invention, and includes respiration detection means for detecting a respiration signal of a subject, and a predetermined threshold value for the time required for the level of the respiration signal to reach a maximum value from 0. A threshold setting means is further provided.

A fourth invention is a control program for an odor presenting system that presents an odor to a subject whose brain activity is measured by an MRI apparatus, wherein a processor of the odor presenting system is provided with imaging processing of the entire head of the subject from the MRI apparatus. a synchronous trigger detection step of detecting a synchronous trigger signal indicating the first start timing of the subject; a respiratory trigger detection step of detecting a respiratory trigger signal indicating the second start timing of inspiration of the subject; A control program for executing an odor presenting step of presenting a predetermined odor to a subject when the time delay of start timing is equal to or less than a predetermined threshold.

A fifth aspect of the present invention is an odor presenting method for presenting an odor to a subject whose brain activity is measured by an MRI apparatus, comprising: (a) indicating a first start timing of imaging processing of the entire head of the subject from the MRI apparatus; (b) detecting a respiratory trigger signal indicative of a second onset of inspiration by the subject; and (c) determining a time delay of the second onset relative to the most recent first onset. is equal to or less than a threshold of, the method of presenting an odor, comprising presenting a predetermined odor to a subject.

According to the present invention, it is possible to reliably detect the rise of the fMRI signal due to the application of the odor stimulus.

The above object, other objects, features and advantages of the present invention will become more apparent from the following detailed description of the embodiments with reference to the drawings.

FIG. 1 is a block diagram showing an example of the electrical configuration of the odor presenting system of the first embodiment. FIG. 2A is an example of a circuit diagram of the respiratory sensor shown in FIG. 1, and FIG. 2B is a configuration of a differential pressure detection unit for detecting the differential pressure between the atmospheric pressure and the respiratory pressure in the respiratory sensor shown in FIG. It is a figure for explaining. FIG. 3 is a diagram showing an example of the configuration of the odor presenting device shown in FIG. FIG. 4 is an example of the configuration of the odor presenting device shown in FIG. 1, and is a diagram for explaining a preparatory state for presenting a certain odor. FIG. 5 is an example of the configuration of the odor presentation device shown in FIG. 1, and is a diagram for explaining a state in which a certain odor is presented. FIG. 6 is a diagram showing an example of temporal changes in the odor selection electromagnetic valve signal, the odor presenting electromagnetic valve signal, the MRI synchronization trigger signal, the respiratory trigger signal, the respiratory trigger signal, and the expected fMRI signal. FIG. 7 is a diagram showing an example of respiratory triggers and presentation timings in temporal changes in respiratory signals when MRI synchronization trigger signals are not considered. FIG. 8 is a diagram showing an example of respiratory triggers and presentation timings in temporal changes in respiratory signals when an MRI synchronization trigger signal is considered. 9 is a diagram showing an example of a memory map of a RAM incorporated in the first control device shown in FIG. 1. FIG. FIG. 10 is a flowchart showing part of an example of odor presenting processing by a CPU incorporated in the first control device shown in FIG. 1; 11 is a flowchart subsequent to FIG. 10, showing another portion of the odor presenting process of the CPU incorporated in the first control device shown in FIG. 1; FIG. FIG. 12 is a flow chart subsequent to FIG. 11, showing another part of the odor presenting process of the CPU incorporated in the first control device shown in FIG.

<First embodiment>
Referring to FIG. 1, an odor presenting system 10 of the first embodiment includes a first control device 12. The first control device 12 includes an input device 14 and a magnetic resonance imaging device (hereinafter referred to as "MRI device"). 16 , signal processing circuit 18 and odor presenting device 22 . Signal processing circuit 18 is also connected to respiratory sensor 20 .

Note that the electrical configuration of the odor presenting system 10 shown in FIG. 1 is merely an example and should not be limited. For example, first controller 12 may be connected to a display device.

The first control device 12 is a computer such as a general-purpose personal computer or workstation, and includes a CPU 30 . CPU 30 is connected to ROM 34 , RAM 36 , HDD 38 , input interface (hereinafter referred to as “input IF”) 40 and communication IF 42 via internal bus 32 .

The CPU 30 manages the overall control of the first control device 12 . The ROM 34 is a non-volatile memory and mainly stores a boot program (activation program) for the first control device 12 . A RAM 36 is a volatile memory and is used as a working area and a buffer area for the CPU 30 . The HDD 38 is a nonvolatile memory and a main storage device of the first control device 12, and stores an operating system and various application programs (including control programs, which will be described later).

As shown in FIG. 1, the input device 14, the MRI device 16 and the signal processing circuit 18 are connected to the input IF40, and the odor presenting device 22 is connected to the communication IF42.

The input IF 40 receives an input signal or operation signal from the input device 14 , an MRI synchronization trigger signal from the MRI apparatus 16 and a respiratory trigger signal from the signal processing circuit 18 , and inputs each signal to the CPU 30 .

The communication IF 42 is an interface (or communication module) for communicating with other computers. In this first embodiment, the CPU 30 of the first controller 12 communicates with the processor (eg, CPU) of the odor presenting device 22 (second controller 220).

Input device 14 is at least one of a keyboard, computer mouse and touchpad (or touch panel).

The MRI apparatus 16 is a general-purpose MRI apparatus, and measures brain activity of a subject based on functional images obtained by fMRI (functional Magnetic Resonance Imaging). Here, fMRI refers to a method of visualizing hemodynamic responses associated with activity of the human brain or spinal cord using MRI (magnetic resonance imaging). In this first embodiment, brain activity based on changes in blood flow of a human subject is measured. That is, fMRI signals (or BOLD signals) are detected.

In the first embodiment, a predetermined number (50 to 70) of functional images are taken of the subject's head (from the tip of the chin to the top of the head) during a first predetermined period of time (2 seconds). However, the imaging position is changed (or moved) each time one functional image is captured, and is moved from the tip of the chin to the top of the head in two seconds. For example, if the number of shots is 60, one functional image is shot every 1/30th of a second. In other words, the MRI apparatus 16 scans the subject's head once every two seconds, during which a plurality of functional images are captured. Then, in the MRI apparatus 16, the scanning operation is repeatedly executed a plurality of times. In this specification, photographing a plurality of functional images in one scan is called "imaging process", and the whole process of repeating it a plurality of times is called "measurement process".

It should be noted that the measurement of brain activity itself is not the essential content of the present invention, and is already well known, so a detailed description of the measurement method and the like will be omitted.

The signal processing circuit 18 includes an amplifier that amplifies the respiratory signal output from the respiratory sensor 20, and a pulse that becomes high level at the timing of the start of inspiration (hereinafter referred to as "at the start") from the amplified respiratory signal by the amplifier. It includes a circuit (a retriggerable monostable multivibrator circuit) for generating a signal (hereinafter "respiration trigger signal").

As for the circuit and method for generating the respiratory trigger signal from the respiratory signal, the circuit and method disclosed in Japanese Patent Application Laid-Open No. 63-79636, previously filed by the applicants of the present application and already published, are adopted. Therefore, a detailed description thereof will be omitted here.

The breathing sensor 20 compares changes in breathing with the atmosphere around the breathing sensor 20, replaces changes in breathing with pressure (hereinafter sometimes referred to as “breathing pressure”) P2, and changes the breathing pressure P2 over time. It is a sensor that outputs as an analog signal. Although not shown, the respiratory sensor 20 includes a housing, which has a port for detecting the atmospheric pressure P1 (hereinafter referred to as "first port") and a port for detecting the respiratory pressure P2. (hereinafter referred to as "second port") is provided. The respiratory sensor 20 is provided in the MRI operation room, one end of a tube for detecting respiratory pressure P2 is connected to the second port, and the other end of the tube is connected to the MRI apparatus 16 set in the MRI shield room. The tube is secured to a nose cone, nose mask, or the like so as to be placed near the nasal cavity of the subject on the bed. Through this tube, a change in respiratory pressure P2 due to respiration of the subject is detected. Since the inside of the tube is filled with air, the movement of the gas at the other end of the tube due to the subject's breathing is linked in real time with the movement of the gas at the one end of the tube. That is, there is no time difference (or time delay) between the subject's breathing and the detection of the respiratory pressure P2 from this breathing.

FIG. 2A is a circuit diagram showing an example of the electrical configuration of the respiratory sensor 20. As shown in FIG. As shown in FIG. 2A, respiratory sensor 20 includes Wheatstone bridge circuit (hereinafter simply referred to as “bridge circuit”) 200 and differential amplifier (hereinafter simply referred to as “amplifier”) 202 . The bridge circuit 200 includes resistors R1, R2, R3 and R4, and the series-connected resistors R1 and R2 and the series-connected resistors R3 and R4 are connected in parallel. A terminal T1 is connected to a connection point between the resistors R1 and R2 and a connection point between the resistors R3 and R4, and an input voltage Vs is applied to the terminal T1. A connection point between the resistors R1 and R4 is connected to the positive input terminal of the amplifier 202, and a connection point between the resistors R2 and R3 is connected to the negative input terminal of the amplifier 202. FIG. One power supply terminal of the amplifier 202 is connected to the terminal T1, and the other power supply terminal of the amplifier 202 is grounded and connected to the terminal T3. The output of amplifier 202 is connected to terminal T2.

The bridge circuit 200 can obtain the output voltage Vx calculated by Equation 1 with respect to the input voltage Vs. An output voltage Vx is applied to the negative input of amplifier 202 .

[Number 1]

The amplifier 202 amplifies the difference between the input voltage at the positive input end and the input voltage at the negative input end (here, the above-described output voltage Vx) by a constant coefficient (differential gain), and outputs the amplified analog voltage (analog signal ) Vout is output from the output end to the terminal T2.

However, the resistor R1 is a piezoresistor included in the piezoelement 200b for detecting the atmospheric pressure P1, and the resistor R3 is a piezoresistor included in the piezoelement 200c for detecting the respiratory pressure P2. As shown in FIG. 2(B), a detection unit (referred to as a “differential pressure detection unit” in FIG. 2(B)) for detecting the difference (differential pressure) Pd between the atmospheric pressure P1 and the respiratory pressure P2 has a plate-like shape. A support (or base material) 200a, a piezoelectric element 200b is attached to one surface of the support 200a, and a piezoelectric element 200c is attached to the other surface of the support 200a. Atmospheric pressure P1 is applied to piezo element 200b through a first port, and breathing pressure P2 is applied to piezo element 200c through a tube and a second port.

Returning to FIG. 2, the odor presenting device 22 is a device for presenting odors to the subject. As shown in FIG. 3, the odor presenting device 22 includes a second controller 220, which turns on (open) and off each of the electromagnetic valves SV1, SV2, SV3, SV4, SV5 and SV6. (closed) and switching (on/off) of the electromagnetic valve SV7. Although not shown, the second control device 220 is a general-purpose computer and includes circuit components such as a CPU, ROM, RAM, HDD, input/output IF, and communication IF.

In this first embodiment, the second controller 220 is communicatively connected to the first controller 12 and controls the on/off of the solenoid valves SV1-SV7 according to commands from the first controller 12. FIG. In FIG. 3, the signal lines for controlling the on/off of the solenoid valves SV1-SV7 are shown in dashed lines to distinguish them from conduits 224-242, which will be described later. 4 and 5, the second control device 220 and the signal line are omitted in order to show the flow of the discharged gas in an easy-to-understand manner. Illustration of the gas flow from the compressor P to the electromagnetic valve SV6 is omitted.

Returning to FIG. 3, the odor presenting device 22 comprises a compressor P and a vacuum pump V, and the compressor P is connected via conduits 224 to the electromagnetic valves SV1-SV6, respectively. Also, the vacuum pump V is connected to an electromagnetic valve SV7. In this first embodiment, the compressor P and the vacuum pump V are started by the user when the process for presenting the odor is started.

Further, in this first embodiment, all of the solenoid valves SV1-SV7 are three-way solenoid valves. The electromagnetic valves SV1-SV6 are turned on when a gas containing an odor component (hereinafter referred to as "odorous gas") is charged and discharged (or an odor is presented), and the ports on the odor cell OD1-OD5 side are turned on. Switched off and switched to an open port when not charging and releasing odorous gas. However, when the electromagnetic valve SV6 is turned on, the electromagnetic valve SV6 is switched to the port connected to the introduction port C6, and the odorless gas is filled and discharged. Also, when the solenoid valve SV6 is turned off, the solenoid valve SV6 is switched to an open port and no odorless gas is charged or discharged.

Further, the solenoid valve SV7 is turned off and switched to the port on the side of the discharge path ME1 when charging the odorous gas, and turned on and switched to the port on the side of the discharge path ME2 when discharging the odorous gas. .

Also, the electromagnetic valve SV1 is connected (or connected) to the odor cell OD1 using a conduit, the electromagnetic valve SV2 is connected to the odor cell OD2 using a conduit, and the electromagnetic valve SV3 is connected to the odor cell OD3 using a conduit. , the solenoid valve SV4 is connected to the odor cell OD4 using a conduit, and the solenoid valve SV5 is connected to the odor cell OD5 using a conduit.

The odor presenting device 22 also includes a nose outlet (hereinafter referred to as “release portion”) 222 that releases odorous gas. The discharge section 222 has a discharge port OL for discharging the gas, introduction ports C1, C2, C3, C4, C5 and C6 for introducing the gas, and discharging the gas to the discharge paths ME1 and ME2. It has outlets C7 and C8 for Each of inlets C1-C6 and outlets C7-C8 and outlet OL are connected by pipe 222a. The ejection part 222 is fixed to a nose cone, a nose mask, or the like so that the ejection port OL is arranged near the nasal cavity of the subject.

A path L1 connecting each of the inlets C1 to C5 and the outlet OL is provided for presenting an odor (releasing an odorous gas), and each path L1 joins in the middle. A path L2 connecting the inlet C6 and the outlet OL is provided to release the odorless gas. Path L3 is part of each of path L1 and path L2, and is a common part of path L1 and path L2. A path L4 branches off from the path L1 and is provided for discharging the odorous gas to the discharge path ME1. Further, a path L5 branches off from the path L2 and is provided for discharging the odorless gas to the discharge path ME2.

However, the discharge path ME1 is composed of a conduit 238, a solenoid valve SV7 and a conduit 242, and the discharge path ME2 is composed of a conduit 240, a solenoid valve SV7 and a conduit 242.

Also, odorant cell OD1 is connected to inlet C1 using conduit 226, odorant cell OD2 is connected to inlet C2 using conduit 228, odorant cell OD3 is connected to inlet C3 using conduit 230, Odor cell OD4 is connected using conduit 232 to inlet C4 and odor cell OD5 is connected using conduit 234 to inlet C5. Solenoid valve SV6 is connected to inlet C6 using conduit 236 . In addition, solenoid valve SV7 is connected using conduit 238 to outlet C7 and using conduit 240 to outlet C8.

Odor cells OD1 to OD5, also called bubblers, contain an odor liquid diluted to a certain concentration with, for example, distilled water (anhydrous solvent) in a pressure vessel made of stainless steel. Furthermore, a passage for odorous gas (that is, odorous gas) (hereinafter referred to as "exhaust passage") is derived from the container stopper. In this first embodiment, each of the odor cells OD1-OD5 accommodates different types of odor liquids. The odor cell OD1 stores the odor liquid of the first odor, the odor cell OD2 stores the odor liquid of the second odor, and the odor cell OD3 stores the odor liquid of the third odor. It is assumed that the odor cell OD4 contains the odor liquid of the fourth odor, and the odor cell OD5 contains the odor liquid of the fifth odor. However, this is only an example, and odor liquids with the same odor may be stored in a plurality of odor cells (two or more of OD1 to OD5).

In addition, the blowing pipes of each odor cell OD1-OD5 are connected to corresponding electromagnetic valves SV1-SV5 via conduits, respectively. Also, the outlet of each odorant cell OD1-OD5 is connected to a corresponding inlet C1-C5 via conduits 226-234, respectively.

In each of the odor cells OD1 to OD5, the odorless gas supplied from the compressor P is blown into the odorant liquid through the blowing pipe to cause bubbling to generate an odorous gas, which is discharged from the discharge channel.

In this specification, a gas that does not contain an odor component or an odorant is called an "odorless gas", as opposed to an odorous gas.

Also, as can be seen from FIG. 3, a portion of the odor presenting device 22 (the emitting portion 222 and a portion of the conduits 226-240) is provided in the MRI shielded room, and the other portion of the odor presenting device 22 is located in the MRI operating room. installed in the room.

That is, in the first embodiment, of the odor presentation system 10, the MRI device 16, part of the odor presentation device 22, and part of the tube for detecting the respiratory pressure P2 are provided in the MRI shield room, and the first Other parts of the control device 12, the input device 14, the signal processing circuit 18, the respiration sensor 20 and the odor presentation device 22 are provided in the MRI operation room.

In such an odor presenting system 10 (smell presenting device 22), when presenting an odor to a subject, the presenting odor is presented before the timing of releasing the odorous gas (presenting the odor). At least the discharge portion 222 is filled with odorous gas. In other words, the process of presenting an odor to a subject includes a step of filling an odorous gas (that is, a state in which the presentation of the odor is prepared) and a step of releasing the odorous gas (that is, the step of actually presenting the odor). state).

For example, when presenting a first odor to a subject, first, an odorous gas for the first odor is filled. Specifically, as shown in FIG. 4, electromagnetic valve SV1 and electromagnetic valve SV6 are turned on. Therefore, the odorless gas supplied from the compressor P is supplied to the odor cell OD1 for the first odor through the electromagnetic valve SV1, and is released from the outlet OL of the release section 222 through the electromagnetic valve SV6. be. Also, when the odorous gas for the first odor is filled, the electromagnetic valve SV7 is turned off and switched to the discharge path ME1 side.

In the odor cell OD1, the odorless gas bubbles the odor liquid of the first odor, and the vacuum pump V causes the odorous gas of the first odor to flow through the path L1 and the path L1 of the pipe 220a in the discharge section 222. It is led out of the odor presenting device 22 via L4, the discharge path ME1 and the electromagnetic valve SV7. In this manner, the odorous gas of the first odor is guided to the discharge path ME1, thereby filling the pipe 220a and the conduit 226 with the odorous gas.

It should be noted that FIG. 4 shows conduit 238 (discharge ME1), solenoid valve SV7, conduit 242 and vacuum pump V in order to better illustrate the odorous gases moving through conduit 238, solenoid valve SV7, conduit 242 and vacuum pump V. It is described slightly shifted from V.

When it comes time to release the odorous gas for the first odor, the electromagnetic valve SV7 is turned on while the electromagnetic valves SV1 and SV6 remain on, as shown in FIG. Then, the electromagnetic valve SV7 is switched to the discharge path ME2 side. Therefore, the odorless gas emitted from the outlet OL is guided to the discharge path ME2 via the path L2 and the path L5 of the pipe 222a, and further to the odor presenting device 22 via the conduit 240 and the electromagnetic valve SV7. Derived externally. As a result, the odorous gas of the first odor is released from the outlet OL. Accordingly, the first odor is presented to the subject. That is, the subject is given a stimulus of the first odor.

It should be noted that FIG. 5 shows conduit 240 (exhaust path ME2), solenoid valve SV7, conduit 242 and vacuum pump V in order to clearly show the odorless gas moving through conduit 240, solenoid valve SV7, conduit 242 and vacuum pump V. It is described with a slight shift from .

Although illustration and detailed description are omitted, when presenting other odors, only the solenoid valves (in this first embodiment, the solenoid valves SV2, SC3, SV4 or SV5) that are turned on are different.

In the first embodiment, an odor is presented to the subject during the period of inspiration (hereinafter referred to as "inspiration period"), and brain activity by odor stimulation is measured. Therefore, the time change of the fMRI signal is detected when the subject is given an odor stimulus.

FIG. 6 is a diagram showing an example of temporal changes in the odor selection electromagnetic valve signal, the odor presenting electromagnetic valve signal, the MRI synchronization trigger signal, the respiration trigger signal, the respiration signal, and the expected fMRI signal.

The odor selection electromagnetic valve signal selects the odor to be presented (the first odor in FIG. 6) and turns on/off the electromagnetic valve (electromagnetic valve SV1 in FIG. 6) for filling and presenting the odor. It is also a signal indicating the timing to turn on/off the electromagnetic valve SV6, which is prepared in advance. The electromagnetic valve SV1 is turned on when the level of the odor selection electromagnetic valve signal changes from low level to high level, and turned off when the level of the odor selection electromagnetic valve signal changes from high level to low level. The electromagnetic valve SV6 is turned on when the level of the odor selection electromagnetic valve signal changes from low level to high level, and turned off when the level of the odor selection electromagnetic valve signal changes from high level to low level.

Although FIG. 6 shows only the odor selection electromagnetic valve signal for the first odor, odor selection electromagnetic valve signals for other odors (second to fifth odors) are also prepared in advance. there is

The odor presenting solenoid valve signal is a signal indicating the timing of turning on/off the odor presenting solenoid valve SV7. The solenoid valve SV7 is turned on when the level of the odor presenting solenoid valve signal changes from low level to high level, and is turned off when the level of the odor presenting solenoid valve signal changes from high level to low level. In this first embodiment, the period during which the odor is presented (hereinafter referred to as "presentation period") is set to a first predetermined time TH1 (2 seconds in this first embodiment).

As can be seen from FIG. 6, the odor selection electromagnetic valve signal and the odor presentation electromagnetic valve signal are changed from high level to low level at the same timing, but it is necessary to fill at least the discharge portion 222 with the odorous gas. Therefore, the timing at which the odor selection solenoid valve signal changes from low level to high level is earlier than the timing at which the odor selection solenoid valve signal changes from low level to high level by the time required for filling (filling time). . For example, the filling time is the second predetermined time TH2 (2 seconds in this first embodiment).

The MRI synchronization trigger signal is a signal input from the MRI apparatus 16, and is a pulse that changes from a low level to a high level at the timing when the imaging process is started each time the measurement process is started and the imaging process is started. signal. Hereinafter, each pulse-shaped signal may be called an MRI synchronization trigger. However, in FIG. 6, line segments are shown instead of pulses. The same is true for respiratory trigger signals.

The respiration trigger signal is an analog respiration signal detected by the respiration sensor 20 and is a pulse signal that becomes high level at the start of inspiration. Hereinafter, each pulse-shaped signal may be referred to as a respiratory trigger. As described above, the respiratory trigger signal is generated by subjecting the respiratory signal to predetermined processing by the signal processing circuit 18 .

The respiratory signal is a signal that indicates the temporal change in respiratory pressure detected by the respiratory sensor 20, as described above. A typical adult breathes 12 to 18 times per minute, so the respiratory cycle is about 3.33 to 3.75 seconds.

In this first embodiment, an odor is presented based on an MRI synchronization trigger signal (MRI synchronization trigger). The scan number corresponds to the number of imaging processes for imaging (scanning) the entire head of the subject with the MRI apparatus 16 . As described above, an image (scan) is taken from the tip of the chin to the top of the head every two seconds, so the MRI synchronization trigger signal goes high every two seconds.

Also, as can be seen from FIG. 6, the odor presenting electromagnetic valve signal is controlled to change from low level to high level in synchronization with the respiration trigger. This is to present the odor during the inspiration period.

However, it is necessary to fill the odorous gas prior to presenting the odor. Also, in this first embodiment, the filling time is the second predetermined time (2 seconds). Therefore, in this first embodiment, the odor selection solenoid valve signal is changed from low level to high level in synchronization with the MRI synchronization trigger. The odor presenting electromagnetic valve signal is changed from low level to high level in synchronization with the respiration trigger after a second predetermined time TH2 (2 seconds) has elapsed since the odor selection electromagnetic valve signal was changed from low level to high level. be changed.

As described above, in the first embodiment, in order to measure brain activity due to odor stimulation, the timing of starting presentation of the odor (that is, the breathing trigger) is the third predetermined time TH3 (this second MRI trigger) from the immediately preceding MRI synchronization trigger. In one embodiment, if there is a delay of 1 second or more, it is not possible to accurately capture the rising portion of the fMRI signal when an odor stimulus is presented.

Therefore, in this first embodiment, when the respiratory trigger signal (scent presenting electromagnetic valve signal) changes from low level to high level, that is, when the respiratory trigger is detected, the MRI synchronization trigger signal is referred to. , the time delay from the immediately preceding MRI synchronization trigger (that is, the start of the current imaging process) is detected, and if this time delay is within a third predetermined time TH3 (1 second), the odor is presented and the time delay exceeds the third predetermined time TH3, the odor is not presented.

Further, since it is empirically known that the fMRI signal has a time constant of about 10 to 12 seconds, the interval from presenting the odor this time to presenting the odor next time is set to a fourth predetermined time TH4 (this fourth predetermined time TH4). In one embodiment, an interval of 12 seconds or more is provided.

Therefore, in FIG. 6, an odor is presented at time t1 and time t2, and it is predicted that the fMRI signal will change due to this odor stimulus. The time at which the odor is presented (hereinafter referred to as "presentation time") is recorded, and from this presentation time, the rising portion of the fMRI signal detected or measured by the MRI apparatus 16 can be accurately known. However, the presentation time is an absolute time when the time when the scent presentation process is started is 0 second.

FIG. 7 is a diagram showing presentation timings and respiratory triggers superimposed on the respiratory signal when an odor is presented in synchronization with the respiratory trigger without considering the MRI synchronization trigger signal. FIG. 8 is a diagram in which presentation timings and respiratory triggers when an odor is presented in synchronization with a respiratory trigger are superimposed on the respiratory signal in consideration of the MRI synchronization trigger signal. However, in both cases of FIGS. 7 and 8, as described above, the scent presentation interval is set to be equal to or longer than the fourth predetermined time TH4 (12 seconds).

In FIGS. 7 and 8, changes in the respiratory signal over time are shown as waveforms, and the solid straight line and the solid circle indicate the timing (time) at which the respiratory trigger signal changes from low level to high level, and the dashed line The straight line and dashed circle indicate the presentation timing, that is, the timing (time) at which the odor stimulus is given.

Also, as can be seen by comparing FIGS. 7 and 8, the number of times the odor is presented is smaller when the MRI synchronization trigger is considered than when the MRI synchronization trigger is not considered. In the case shown in FIG. 7, the smell presentation interval has an average value of 14 seconds, a minimum value of 12.1 seconds, and a maximum value of 18.5 seconds. Also, in the case shown in FIG. 7, the ratio of the number of times the odor was presented to all the number of respiratory triggers is 25%. On the other hand, in the case shown in FIG. 8, the smell presentation interval has an average value of 18 seconds, a minimum value of 12.1 seconds, and a maximum value of 33.9 seconds. Also, in the case shown in FIG. 8, the ratio of the number of times the odor was presented to all the number of respiratory triggers is 19%.

In this way, when the MRI synchronization trigger is considered, the number of times the odor is presented can be reduced compared to when the MRI synchronization trigger is not considered. That is, it is possible to omit useless odor presentation and fMRI signal detection for useless odor stimulation.

FIG. 9 is a diagram showing an example of a memory map 300 of the RAM 36 incorporated in the first control device 12 shown in FIG. As shown in FIG. 9, RAM 36 includes program storage area 302 and data storage area 304 . The program storage area 302 stores a control program for the odor presentation system 10, which is an example of an information processing program. The control programs include an MRI synchronization trigger detection program 302a, a breathing trigger detection program 302b, an odor filling program 302c, and an odor presentation program 302d. and so on.

The MRI synchronization trigger detection program 302 a is a program for detecting an MRI synchronization trigger signal output from the MRI apparatus 16 and storing it in the data storage area 304 . The respiratory trigger detection program 302 b is a program for detecting respiratory trigger signals and storing them in the data storage area 304 .

The odor filling program 302c is a program for filling odorous gas for the selected odor at the timing when the MRI synchronization trigger signal changes from low level to high level, that is, in synchronization with the MRI synchronization trigger. be. Specifically, according to the odor filling program 302c, one of the electromagnetic valves SV1 to SV5 corresponding to the selected odor is turned on, the electromagnetic valve SV6 is turned on, and the electromagnetic valve SV7 is turned off. However, in the first embodiment, when the odor filling program 302c starts the odor presenting process, the odor filling program 302c starts filling the odor in synchronization with the third trigger of the MRI synchronization trigger signal. However, from the second time onwards, odor filling is started in synchronism with the trigger of the MRI synchronization trigger signal first detected 12 seconds after the presentation of the previous odor. Also, the odor is selected by a selection electromagnetic valve signal prepared in advance.

The odor presentation program 302d synchronizes with the first detected respiratory trigger after the odor filling time has passed the second predetermined time TH2 (2 seconds), and the delay time with respect to the most recent MRI synchronization trigger is the third predetermined time. This is a program for presenting an odor for a first predetermined time TH1 (2 seconds) when the time is less than or equal to TH3 (1 second). Specifically, one of the electromagnetic valves SV1 to SV5 and the electromagnetic valve SV6 that have been turned on according to the odor filling program 302c are kept on, the electromagnetic valve SV7 is turned on, and this state is maintained for 2 seconds. do. However, the smell presenting program 302d is also a program for not presenting the smell when the delay time exceeds the third predetermined time TH3 (1 second). When no odor is presented, any one of the electromagnetic valves SV1 to SV5 and the electromagnetic valve SV6 that have been turned on according to the odor charging program 302c are turned off, and the electromagnetic valve SV7 is kept off.

Although not shown, the program storage area 302 also stores other programs necessary for controlling the operation of the first control device 12 .

The data storage area 304 stores MRI synchronization trigger data 304a, respiratory trigger data 304b, and presentation time data 304c. The data storage area 304 is also provided with an absolute time timer 304d, a filling timer 304e, a delay timer 304f, a presentation timer 304g and an interval timer 304h.

The MRI synchronization trigger data 304a is data on the MRI synchronization trigger signal and is stored in chronological order. The respiratory trigger data 304b is data about the respiratory trigger signal and is stored in chronological order. The presentation time data 304c is data about the time (presentation time) when the scent is presented. However, since the scent is presented multiple times, the presentation time data 304c includes presentation time data for each time. As described above, the presentation time for each time is recorded as an absolute time from the start of the scent presentation process (the start time is set to 0 seconds).

The absolute time timer 304d is a timer for counting the absolute time after the scent presentation process is started. The filling timer 304e is a timer for counting the filling time. The delay timer 304f is a timer for counting delay time. The presentation timer 304g is a timer for counting the scent presentation period. The interval timer 304h is a timer for counting the time interval to be provided from the end of the presentation of the present scent to the presentation of the next scent.

Although not shown, the data storage area 304 stores other data necessary for executing the control program, and is provided with other timers (counters) and flags necessary for executing the control program.

10 to 12 are flow charts showing an example of odor presenting processing of the CPU 30 incorporated in the first control device 12 shown in FIG. As shown in FIG. 10, when starting the scent presentation process, the CPU 30 resets and starts the absolute time timer 304d in step S1.

Subsequently, in step S3, it is determined whether or not it is time to start scent filling. Here, the CPU 30 refers to the MRI synchronization trigger data 304a stored in the data storage area 304 to determine whether the current (latest) MRI synchronization trigger has been detected. The same is true for determining whether or not an MRI synchronization trigger has been detected. However, if the odor is filled and presented for the first time, the CPU 30 determines whether or not the third MRI synchronization trigger has been detected.

Although not shown, the CPU 30 detects an MRI synchronization trigger signal and a respiratory trigger signal in parallel with the odor presentation processing, and detects MRI synchronization trigger data 304a and MRI synchronization trigger data 304a corresponding to the detected MRI synchronization trigger signal and respiratory trigger signal. A process of storing the respiration trigger data 304b in the data storage area 304 is executed.

If "NO" in step S3, that is, if it is not the time to start scent filling, the process returns to step S3. On the other hand, if "YES" in step S3, that is, if it is the scent filling start timing, the second controller 220 is instructed to start scent filling in step S5. Specifically, the CPU 30 instructs the second control device 220 to turn on any one of the electromagnetic valves V1 to V5 for the odor to be presented and the electromagnetic valve V6, and to turn off the electromagnetic valve V7.

In the next step S7, the filling timer 304e is reset and started, and in step S9, it is determined whether the filling time has passed a second predetermined time TH2 (for example, 2 seconds). In this step S9, the CPU 30 determines whether or not the count value of the filling timer 304e has passed two seconds. If "NO" in step S9, that is, if the filling time has not passed the second predetermined time TH2, the process returns to step S9. On the other hand, if "YES" in step S9, that is, if the filling time has passed the second predetermined time, it is determined in step S11 whether or not an MRI synchronization trigger has been detected.

If "NO" in step S11, that is, if the MRI synchronization trigger is not detected, the process returns to step S11. On the other hand, if "YES" in step S11, that is, if an MRI synchronization trigger is detected, then in step S13 the delay timer 304f is reset and started, and in step S15 shown in FIG. to judge what In this step S15, the CPU 30 refers to the breathing trigger data 304b to determine whether or not the current breathing trigger has been detected.

If "NO" in step S15, that is, if no respiratory trigger has been detected, it is determined in step S17 whether or not the next MRI synchronization trigger has been detected. Here, the next MRI synchronization trigger means the MRI synchronization trigger detected next to the MRI synchronization trigger determined to be detected in step S11.

If "NO" in step S17, that is, if the next MRI synchronization trigger is not detected, the process returns to step S15. On the other hand, if "YES" in step S15, that is, if a respiratory trigger is detected, it is determined in step S19 whether the delay time is within a third predetermined time TH3 (for example, 1 second). In this step S19, the CPU 30 determines whether the count value of the delay timer 304f is within 1 second.

If "NO" in step S19, that is, if the delay time has passed the third predetermined time TH3, it is determined that the scent is not to be presented, and in step S21, the second controller 220 stops filling the scent. direct to. Here, the CPU 30 instructs the second control device 220 to turn off any one of the electromagnetic valves V1 to V5 instructed to be turned on in step S5 and the electromagnetic valve V6.

On the other hand, if "YES" in step S19, that is, if the delay time is within the third predetermined time TH3, it is determined to present the odor, and in step S23, the second controller 220 is instructed to present the odor. . In this step S23, the CPU 30 maintains the on state of any one of the electromagnetic valves V1 to V5 instructed to be turned on in step S5 and the electromagnetic valve V6, and turns on the electromagnetic valve V7 as the second control. Instruct device 220 .

In the next step S25, the presentation time is recorded. That is, CPU 30 acquires the count value of absolute time timer 304 d as the presentation time, and stores data corresponding to the presentation time in data storage area 304 .

Subsequently, in step S27, the presentation timer 304g is reset and started, and in step S29 shown in FIG. 12, it is determined whether or not the presentation time has passed the first predetermined time TH1 (for example, 2 seconds). In this step S29, the CPU 30 determines whether or not the count value of the presentation timer 304g has passed two seconds.

If "NO" in step S29, that is, if the presentation time has not passed the first predetermined time TH1, the process returns to step S29. On the other hand, if "YES" in step S29, that is, if the presentation time has passed the first predetermined time TH1, the interval timer 304h is reset and started in step S31. Subsequently, in step S33, the second control device 220 is instructed to end presenting the scent this time. In this step S33, the CPU 30 instructs the second control device 220 to turn off any one of the electromagnetic valves V1 to V5 and the electromagnetic valves V6 and V7 instructed to be turned on in step S23.

Then, in step S35, it is determined whether or not the processing is finished. Here, CPU 30 determines whether or not the user has instructed to end the odor presenting process. In another embodiment, the CPU 30 may determine to end the odor presentation process when the MRI synchronization trigger is not detected for a predetermined time (for example, 10 seconds).

If "NO" in step S35, that is, if not finished, in step S37, it is determined whether or not a fourth predetermined time TH4 (for example, 12 seconds) has elapsed since the previous presentation. Here, the CPU 30 determines whether the count value of the interval timer 304h has passed 12 seconds.

If "NO" in step S37, that is, if the fourth predetermined time TH4 has not elapsed since the previous presentation, the process returns to step S35. On the other hand, if "YES" in step S37, that is, if the fourth predetermined time TH4 has elapsed since the previous presentation, the process returns to step S3 shown in FIG.

According to the first embodiment, the odor is presented to the subject not only in accordance with the inhalation period of the subject, but also in consideration of the start timing of the imaging process of the MRI apparatus. A rise can be detected reliably. In other words, it is possible to correctly measure the brain activity of the subject due to the odor stimulation.

<Second embodiment>
The odor presenting system of the second embodiment is the same as the first embodiment except that a predetermined threshold for determining whether or not to present an odor, that is, the third predetermined time TH3 is set for each subject. , different contents will be explained, and explanations of overlapping contents will be omitted.

In the second embodiment, before the odor is presented, the subject's respiratory signal is detected for a predetermined time (for example, 60 seconds), and based on the detected respiratory signal, the time of the subject's maximum respiration (inhalation) flow rate is detected. be done. In this first embodiment, the maximum flow rate time is set as the maximum value of the delay time.

However, in the second embodiment, the time of maximum respiratory flow means the time from the level of the respiratory signal to the maximum value.

In the detected respiration signal, the time of the maximum flow is detected for each breath, and the average value of the time of the maximum flow of each time is set as the maximum value of the delay time. However, the average value is an example, and other statistics may be used.

In the odor presentation system 10 of the second embodiment, the respiratory signal output from the respiratory sensor 20 is amplified, and the amplified respiratory signal is also input to the first controller 12 . The first controller 12 calculates the maximum value of the delay time based on the respiratory signal of the subject before presenting the odor. The maximum value of this delay time is determined as the third predetermined time TH3 (that is, the threshold value), and is used in the judgment processing (S19) of whether or not to present the odor.

In the second embodiment, the program storage area 302 further stores a program for setting the third predetermined time TH3 based on the respiratory signal detected in advance (hereinafter referred to as "setting program"). , and before step S1 of the odor presenting process shown in FIGS. 10 to 12, the setting process of the third predetermined time TH3 according to the setting program is executed. Therefore, in step S19, the determination process is executed using the third predetermined time TH3 set by the setting process.

According to the second embodiment, a threshold value for determining whether or not to present an odor is set for each subject. Therefore, in addition to the effects of the first embodiment, the control of presenting the odor according to the subject's breathing is achieved. It can be performed.

It should be noted that the specific numerical values shown in each of the above-described examples are merely examples and should not be limited, and can be changed as appropriate according to the product or the like to be implemented.

DESCRIPTION OF SYMBOLS 10... Odor presentation system 12... 1st control apparatus 14... Input device 16... MRI apparatus 20... Breathing sensor 22... Odor presentation apparatus 30... CPU
34 ... ROM
36 RAM
38 HDD
40 ... Input IF
42 ... Communication IF
220 ... second control device 222 ... discharge section SV1, SV2, SV3, SV4, SV5, SV6, AV7 ... electromagnetic valve P ... compressor V ... vacuum pump

Claims (5)

An odor presentation system for presenting an odor to a subject whose brain activity is measured by an MRI apparatus,
Synchronous trigger detection means for detecting a synchronous trigger signal indicating a first start timing of imaging processing for the entire head of the subject from the MRI apparatus;
respiratory trigger detection means for detecting a respiratory trigger signal indicating a second start timing of inspiration of the subject;
An odor presenting system comprising odor presenting means for presenting a predetermined odor to the subject when the time delay of the second start timing with respect to the most recent first start timing is equal to or less than a predetermined threshold. Further comprising a filling means for filling the odor releasing portion with gas of the predetermined odor prior to presenting the predetermined odor,
2. The smell presenting system according to claim 1, wherein said breathing trigger detection means detects said breathing trigger signal in response to filling of said gas of said predetermined smell into said filling means by said filling means. respiration detection means for detecting a respiration signal of the subject;
3. The smell presenting system according to claim 1, further comprising threshold setting means for setting the time required for the level of said respiratory signal to reach a maximum value from 0 to said predetermined threshold. A control program for an odor presentation system that presents an odor to a subject whose brain activity is measured by an MRI apparatus,
In the processor of the odor presentation system,
a synchronous trigger detection step of detecting a synchronous trigger signal indicating a first start timing of imaging processing for the entire head of the subject from the MRI apparatus;
a respiratory trigger detection step of detecting a respiratory trigger signal indicating a second start timing of inspiration of the subject;
A control program for executing an odor presenting step of presenting a predetermined odor to the subject when the time delay of the second start timing with respect to the most recent first start timing is equal to or less than a predetermined threshold. An odor presentation method for presenting an odor to a subject whose brain activity is measured by an MRI apparatus,
(a) a step of detecting a synchronization trigger signal indicating a first start timing of imaging processing for the entire head of the subject from the MRI apparatus;
(b) detecting a respiratory trigger signal indicative of a second initiation timing of inspiration for the subject;
(c) An odor presenting method, including the step of presenting a predetermined odor to the subject when the time delay of the second start timing with respect to the most recent first start timing is equal to or less than a predetermined threshold.

Images