JP2023066196A - Detection device, gas analyzer, and method of using detection device - Google Patents

Abstract

To provide a detection device which offers improved detection sensitivity, a gas analyzer, and a method of using the detection device.SOLUTION: A detection device is provided, comprising an ionization unit configured to ionize gas by corona discharge, an ion filter configured to selectively allow a portion of ions ionized by the ionization unit to pass, an ion detection electrode configured to collide with the ions ionized by the ionization unit and allowed to pass through the ion filter, and a discharge unit configured to selectively discharge a portion of the ions generated by the corona discharge.SELECTED DRAWING: Figure 4

Description

The present invention relates to detection devices, gas analyzers and methods of using detection devices.

Various studies have been conducted on the detection and analysis of molecules by Field Asymmetric Ion Mobility Spectrometry (FAIMS) systems. The FAIMS system has an ion filter with a pair of electrodes to which an asymmetric alternating signal is applied, and ionized gas molecules flow through the ion filter and are sorted by their mobility difference. By causing the ions that have passed through the ion filter to collide with the ion detection electrode and detecting the current generated by the ion detection electrode, the components of the gas can be specified.

A method using corona discharge has been proposed as a method for ionizing gas molecules.

Conventionally, when gas molecules ionized by corona discharge are used in a FAIMS system, sufficient detection sensitivity cannot be obtained.

An object of the present invention is to provide a detection device, a gas analysis device, and a method of using the detection device that can improve detection sensitivity.

According to one aspect of the disclosed technology, a detection device includes an ionization section that ionizes gas by corona discharge, an ion filter that selectively transmits a part of the ions ionized by the ionization section, and the ionization section. It has an ion detection electrode that collides with ions that have been ionized and have passed through the ion filter, and an ejection section that selectively ejects a portion of the ions generated by the corona discharge.

According to the technology disclosed, detection sensitivity can be improved.

FIG. 4 is a diagram showing trajectories of movement of ions in an example of an ion filter; It is a figure which shows the electric field strength dependence of the mobility of ion. It is a figure which shows an example of the electric field waveform which generate|occur|produces with an ion filter. 1 is a schematic diagram showing a detection device according to a first embodiment; FIG. FIG. 3 is a cross-sectional view showing the ionizer, ion filter, and ion detection electrodes in the first embodiment; FIG. 4 shows an example of an asymmetric voltage waveform for implementing the example of the electric field waveform shown in FIG. 3; FIG. 4 is a diagram showing another example of an asymmetric voltage waveform for realizing the example of the electric field waveform shown in FIG. 3; FIG. 5 is a cross-sectional view showing an ionizer, an ion filter, and ion detection electrodes in a second embodiment; FIG. 11 is a cross-sectional view showing an ionizer, an ion filter, and ion detection electrodes in a third embodiment; FIG. 11 is a cross-sectional view showing an ionizer, an ion filter, and ion detection electrodes in a fourth embodiment; It is a cross-sectional view showing a toilet apparatus according to a fifth embodiment.

Embodiments of the present disclosure will be described below with reference to the accompanying drawings. In the present specification and drawings, constituent elements having substantially the same functional configuration may be denoted by the same reference numerals, thereby omitting redundant description.

(Ion detector)
First, the configuration and basic principle of an ion filter used in the FAIMS system will be described. FIG. 1 is a diagram showing trajectories of ion movement in an example of an ion filter. FIG. 2 is a diagram showing electric field intensity dependence of ion mobility. FIG. 3 is a diagram showing an example of an electric field waveform generated by an ion filter.

As shown in FIG. 1, the ion filter 120A has a first electrode 121A and a second electrode 122A facing each other. For example, an ion detection electrode 130A is arranged after the ion filter 120A.

An ion current detection circuit is connected to the ion detection electrode 130A. A current is generated according to the amount of ions that collide with the ion detection electrode 130A, and this current is detected by the ion current detection circuit. Here, an XYZ three-dimensional orthogonal coordinate system is used, the traveling direction of the molecule to be analyzed is the +Z direction, the direction in which the second electrode 122A can be seen from the first electrode 121A is the +Y direction, and the direction orthogonal to the +Y and +Z directions. is the +X direction.

Ions move at a moving speed V represented by the following equation (1) under an electric field E environment. where K is the mobility of the ion.
V=K×E (1)

By the way, the mobility of ions depends on the electric field strength. This electric field strength dependence differs depending on the type of ion. FIG. 2 shows, as an example, the electric field intensity dependence of the mobility of three ions (ions 11, 12, and 13) of different types. In FIG. 2, for the sake of clarity, the ions are normalized so that the mobilities of the ions are equal when the electric field strength is zero.

The mobilities of the three ions (ion 11, ion 12, and ion 13) are almost unchanged at low electric field strengths of 9 kV/cm or less. As the electric field strength increases from about 10 kV/cm, ion type-specific properties appear in the mobility. The mobility of ions 11 increases greatly with increasing field strength and is maximum at high positive fields (Emax). The mobility of the ions 12 hardly changes regardless of the electric field strength. The mobility of ions 13 decreases slowly. In this way, it exhibits three different characteristics. The ion filter 120A selects ions by using the difference between the mobility at low electric field strength and the mobility at high electric field strength.

FIG. 1 shows trajectories of movement of three ions (ions 11, 12, and 13) between the first electrode 121A and the second electrode 122A of the ion filter 120A. Here, for the sake of clarity, the first electrode 121A and the second electrode 122A are assumed to be parallel flat plates made of conductors.

By making the waveform of the electric field generated between the first electrode 121A and the second electrode 122A an asymmetric electric field waveform, only arbitrary ions (ions 12 in FIG. 1) can reach the ion detection electrode 130A. .

FIG. 3 shows an example of an electric field waveform generated between the first electrode 121A and the second electrode 122A. This electric field waveform alternates between a positive high electric field (Emax) and a negative low electric field (Emin). The high electric field period (t1) is shorter than the low electric field period (t2), and the ratio between t1 and t2 is 1:3 to 1:5. Thus, the electric field waveform is vertically asymmetrical. This asymmetric electric field waveform has a time-averaged electric field of zero and is set so that the following equation (2) holds.
|Emax|×t1=|Emin|×t2 (2)

That is, the area of the area 21 and the area of the area 22 in FIG. 3 are set to match.

In the following description, the value of |Emax|×t1 and the value of |Emin|×t2 are assumed to be β, as shown in the following equation (3).
|Emax|×t1=|Emin|×t2=β (3)

By the way, the velocity (Vup) at which ions move in the Y-axis direction during the high electric field period (t1) is given by the following equation (4). where K(Emax) is the ion mobility at high electric field (Emax).
Vup=K(Emax)×|Emax| (4)

For example, when |Emax| is about 10 kV/cm or more, three ions (ion 11, ion 12, and ion 13) have different mobilities. Three different. That is, as shown in FIG. 1, during the high electric field period (t1), the inclinations of the three ion trajectories are different from each other.

The displacement (yup), which is the distance that ions move in the Y-axis direction during the high electric field period (t1), is given by the following equation (5).
yup=Vup×t1 (5)

On the other hand, the velocity (Vdown) at which the ions move in the Y-axis direction during the low electric field period (t2) is given by the following equation (6). where K(Emin) is the ion mobility at low electric field (Emin).
Vdown=−K(Emin)×|Emin| (6)

For example, when the |Emin| is. That is, as shown in FIG. 1, during the low electric field period (t2), the slopes of the trajectories of the three ions are almost the same.

The displacement (ydown), which is the distance that the ions move in the Y-axis direction during the low electric field period (t2), is given by the following equation (7).
ydown=Vdown×t2 (7)

Within one period (T) of the asymmetric electric field waveform, ions move in the +Z direction, move in the +Y direction during the period (t1), and move in the -Y direction during the period (t2).

Therefore, as shown in FIG. 1, one (ion 11) moving toward the first electrode 121A while repeating the zigzag movement, one (ion 13) moving toward the second electrode 122A while repeating the zigzag movement, and displacement in the +Y direction. and the displacement in the -Y direction are balanced, and are classified into those (ions 12) directed toward the ion detection electrode 130A.

By the way, the average displacement (ΔyRF) of ions in the Y-axis direction in one period (T) in the asymmetric electric field waveform is expressed by the following equation (8).
ΔyRF=yup+ydown
=K(Emax)×|Emax|×t1−K(Emin)×|Emin|×t2
... (8)

The above equation (8) can be expressed as the following equation (9) using the above equation (3).
ΔyRF=β{K(Emax)−K(min)} (9)

Here, if K(Emax)-K(min) is ΔK, the above equation (9) is expressed as the following equation (10).
ΔyRF=βΔK (10)

β is a constant determined by the asymmetric electric field applied between the first electrode 121A and the second electrode 122A. Therefore, the displacement of ions in the Y-axis direction per period (T) of the asymmetric electric field waveform depends on ΔK, which is the difference between the mobility in the low electric field (Emin) and the mobility in the high electric field (Emax).

Assuming that only the carrier gas transports ions in the Z-axis direction, the displacement (Y) of the ions in the Y-axis direction when the ions are staying between the first electrode 121A and the second electrode 122A is , is given by the following equation (11). Here, tres is the average time that ions stay between the first electrode 121A and the second electrode 122A (average ion residence time).

The average ion residence time tres is represented by the following equation (12). Here, A is the cross-sectional area of the ion path in the ion filter 120A, L is the length of the electrode in the Z-axis direction (electrode depth), and Q is the volumetric flow rate of the carrier gas. V is the volume (=A×L) of the ion filter 120A.

The above equation (11) can be expressed as the following equation (13) using the above equations (12) and (3). Here, D is the duty of the asymmetric electric field waveform, and D=t1/T.

The high electric field (Emax) in the asymmetric electric field waveform, the volume (V) of the ion path in the ion filter 120A, the duty (D) of the asymmetric electric field waveform, and the volumetric flow rate (Q) of the carrier gas are the same for all ion species. (13), the displacement (Y) is proportional to the difference ΔK between the ion species-specific mobility at a low electric field (Emin) and at a high electric field (Emax). Recognize.

In FIG. 1, the displacement (Y) of the ions 12 is the smallest, and only the ions 12 reach the ion detection electrode 130A. can reach the ion detection electrode 130A. Further, by gradually changing the duty (D), it is possible to detect the presence and amount of various ions with different ΔK.

By changing the dispersion voltage (VDF), which is the difference between the high electric field (Emax) and the low electric field (Emin), while keeping the duty (D) constant, the presence and amount of various ions with different ΔK can be detected. can be done.

Also, by superimposing a low intensity DC electric field on the asymmetric electric field waveform, various ion species with different ΔK can be detected. According to this method, it is possible to change the amount of displacement in the Y-axis direction during the period (t1) and the period (t2). Therefore, it is possible to continuously change the ion species that can reach the ion detection electrode 130A without contacting the first electrode 121A or the second electrode 122A. Note that the DC electric field superimposed on the asymmetric electric field waveform is called compensation voltages (CV). In this method, the compensation voltage is swept to detect the presence and amount of various ion species with different ΔK.

By collecting data on the amount of ions detected under conditions in which various values of the dispersion voltage and the compensation voltage are combined, it is possible to more accurately analyze the presence or absence of various ion species.

By the way, ions that come into contact with the first electrode 121A or the second electrode 122A before reaching the ion detection electrode 130A are neutralized and are not detected as ions.

Thus, the ion filter 120A can be used to selectively allow ions to reach the ion detection electrode 130A.

(First embodiment)
Next, a first embodiment will be described. The first embodiment relates to a detection device to which the FAIMS system is applied. FIG. 4 is a schematic diagram showing the detection device according to the first embodiment. FIG. 5 is a cross-sectional view showing the ionizer, ion filter, and ion detection electrodes in the first embodiment.

As shown in FIGS. 4 and 5, the detection device 100 according to the first embodiment has an ionizer 110, an ion filter 120, an ion detection electrode 130, a housing 140, and an exhaust section 150. FIG. Ionizer 110 , ion filter 120 and ion detection electrode 130 are housed in housing 140 . The ionizer 110 , the ion filter 120 and the ion detection electrode 130 are arranged in this order from the inlet 141 to the outlet 142 of the housing 140 . The detection device 100 further includes an ion current detection circuit 161 , an asymmetric waveform signal generation circuit 162 and a compensation voltage generation circuit 163 .

The ion filter 120 has a rectangular plate shape and includes a first electrode 121 and a second electrode 122 . The material of the first electrode 121 and the second electrode 122 is, for example, a metal or a semiconductor imparted with conductivity by impurities. The first electrodes 121 and the second electrodes 122 are alternately arranged in a comb shape and face each other in a direction parallel to the plate surface. A gap of about 10 μm to 50 μm, for example, exists between the first electrode 121 and the second electrode 122 . A cylindrical first opening 151 is formed in the center of the ion filter 120 when viewed from the direction perpendicular to the plate surface. The diameter of the first opening 151 is, for example, about 1 mm. The first opening 151 is formed over both the first electrode 121 and the second electrode 122 . The first opening 151 is an example of a first exhaust port.

An asymmetric waveform signal generation circuit 162 and a compensation voltage generation circuit 163 are connected to the first electrode 121 and the second electrode 122 . The asymmetric waveform signal generation circuit 162 supplies the first electrode 121 and the second electrode 122 with an asymmetric voltage waveform signal for realizing the example of the asymmetric electric field waveform shown in FIG. A signal P1 is supplied from the asymmetric waveform signal generation circuit 162 to the first electrode 121 , and a signal P2 is supplied from the asymmetric waveform signal generation circuit 162 to the second electrode 122 . A compensation voltage generation circuit 163 supplies the offset voltage and the compensation voltage to the first electrode 121 and the second electrode 122 . A signal CV1 is supplied from the compensation voltage generation circuit 163 to the first electrode 121, and a signal CV2 is supplied from the compensation voltage generation circuit 163 to the second electrode 122. FIG.

Here, a signal with an asymmetrical voltage waveform will be described. FIG. 6 is a diagram showing an example of an asymmetric voltage waveform for realizing the example of the electric field waveform shown in FIG. In the example shown in FIG. 6, a signal P1 having a constant voltage (here, 0 V) is supplied to the first electrode 121, and a high-frequency waveform signal P2 having a period T and pulse widths t1 and t2 equal to those of the asymmetric waveform electric field in FIG. It is supplied to the second electrode 122 . The amplitude of the high-frequency waveform signal P2 is Vmax to -Vmin corresponding to Emax to Emin.

As shown in FIG. 4, signals P1 and P2 are applied to first electrode 121 and second electrode 122, respectively, through capacitors. Therefore, only the AC component of the asymmetric voltage waveform is transmitted to the first electrode 121 and the second electrode 122 . Also, the signals CV1 and CV2 are supplied to the first electrode 121 and the second electrode 122 through resistors, respectively. Therefore, the average voltage of the signal applied to the first electrode 121 is the voltage of the signal CV1, and the average voltage of the signal applied to the second electrode 122 is the voltage of the signal CV2.

The ionizer 110 ionizes the sample gas by corona discharge. A sample gas is a gas containing gas molecules to be detected. The ionizer 110 has a discharge needle 111 and a ground electrode 112 . The discharge needle 111 is arranged closer to the inlet 141 than the ion filter 120 is. The ground electrode 112 is provided inside the first opening 151 . A gap exists between the ground electrode 112 and the inner wall of the first opening 151 . A straight line passing through the discharge needle 111 and the ground electrode 112 is substantially perpendicular to the plate surface of the ion filter 120 . The detection device 100 has a power supply 164 that applies voltage to the discharge needle 111 . A corona discharge is generated between the discharge needle 111 and the ground electrode 112 by applying a voltage from the power supply 164 to the discharge needle 111 . When corona discharge occurs, NO _x , NO _x ^- , and OH ^- are generated from ambient nitrogen gas and oxygen gas. At this time, in the direction parallel to the plate surface of the ion filter 120, NO _x and NO _x ⁻ are concentrated in a region 113 near the ground electrode 112, and OH ⁻ is generated in a region 114 slightly away from the ground electrode 112. occur intensively. The first opening 151 is formed so as to overlap the region 113 and the region 114 is located outside the first opening 151 when viewed from the direction perpendicular to the plate surface of the ion filter 120 . The ionizer 110 is an example of an ionization section.

The ion detection electrode 130 has a rectangular plate shape. A cylindrical second opening 152 is formed in the center of the ion detection electrode 130 when viewed in a direction perpendicular to the plate surface. The second opening 152 communicates with the first opening 151 . The diameter of the second opening 152 is, for example, about 1 mm. The second opening 152 is an example of a second exhaust port. A first opening 151 and a second opening 152 are included in the discharge portion 150 .

The ion current detection circuit 161 is connected to the ion detection electrode 130 . The ion current detection circuit 161 detects the magnitude of current generated according to the amount of ions that collide with the ion detection electrode 130 .

In the detection device 100 according to the first embodiment, the sample gas is introduced into the housing 140 through the inlet 141 . A sample gas introduced into the housing 140 is ionized by the ionizer 110 . Due to the action of the ion filter 120, part of the ionized sample gas (ions) reaches the ion detection electrode 130, and a current is generated according to the amount of ions that collide with the ion detection electrode 130. This current is the ion current. It is detected by the detection circuit 161 . Therefore, by controlling the ion filter 120 so that only ions of gas molecules to be detected (for example, hydrogen sulfide) contained in the sample gas pass through the ion filter 120, the amount of gas molecules to be detected can be specified. Also, the sample gas is discharged to the outside from the outlet 142 .

Here, the ionization of the sample gas will be explained. As described above, corona discharge generates NO _x , NO _x ^- and OH ^- . The proton affinity of OH ^- is greater than that of NO _x ^- . Therefore, OH ⁻ withdraws protons from the sample gas, and the sample gas becomes negatively ionized. As a result, OH ^- becomes a molecule such as H ₂ O. On the other hand, NO _x ^- is difficult to extract protons from the sample gas, and NO _x ^- exists as ions. Therefore, NO _x ^- does not contribute to the detection of gas molecules to be detected.

Also, before actual measurement using the detection device 100, the ion current detection circuit 161 connected to the detection device 100 is calibrated. During this calibration, corona discharge is generated without supplying sample gas and without operating the ion filter 120 . The setting of the ion current detection circuit 161 is adjusted so that the current detected by the ion current detection circuit 161 when the ions generated by this corona discharge collide with the ion detection electrode 130 is maximized.

During calibration, if NO _x ^- collides with the ion sensing electrode 130, an adjustment will be made that also reflects the amount of NO _x ^- . In particular, if the amount of NO _x ^- predominates, an adjustment will be made which is substantially suitable for detection of the amount of NO _x ^- . In this case, during actual measurement, even if the ion filter 120 prevents NO _x ⁻ from colliding with the ion detection electrode 130, the current corresponding to the amount of gas molecules to be detected becomes small. of gas molecules cannot be detected with high sensitivity.

Therefore, in calibrating the ion current detection circuit 161, the discharge unit 150 is used to discharge NO _x ⁻ from the outlet 142 so that the NO _x ⁻ does not collide with the ion detection electrode 130 as much as possible. That is, during calibration, although NO _x ^- is generated by corona discharge, NO _x ^- does not collide with the ion detection electrode 130 through the first opening 151 and the second opening 152 and reaches the outlet 142 of the housing 140 . Move and eject. On the other hand, OH ⁻ generated by corona discharge is allowed to collide with the ion detection electrode 130 through the ion filter 120 , and the ion current detection circuit 161 detects the current generated when OH ⁻ collides with the ion detection electrode 130 . In this state, the setting of the ion current detection circuit 161 is adjusted so that the current detected by the ion current detection circuit 161 becomes as large as possible. For example, the gain of current/voltage conversion in the ion current detection circuit 161 and the dynamic range and resolution of digital-analog conversion are adjusted. This adjustment will be made mainly according to the amount of ^OH- . As mentioned above, the ionization of the sample gas is done by ^OH- . Therefore, the setting of the ion current detection circuit 161 is adjusted to suit detection of the amount of sample gas (ions) ionized by OH ⁻ . Therefore, in actual measurement, the amount of gas molecules to be detected can be detected with high sensitivity.

In addition, when NO _x generated by corona discharge and sample gas (ions) ionized by OH ⁻ are mixed during actual measurement, NO _x gives protons to the ionized sample gas (ions). As a result, the sample gas (ions) may be neutralized. In the present embodiment, NO _x generated by corona discharge is also discharged from the discharge part 150, so NO _x generated by corona discharge and the sample gas (ions) ionized by OH ⁻ are less likely to mix. Therefore, it is possible to suppress the neutralization of the sample gas (ions) and suppress the decrease in the detection sensitivity that accompanies the neutralization.

It should be noted that the signal of the asymmetric voltage waveform is not limited to the example shown in FIG. FIG. 7 is a diagram showing another example of an asymmetric voltage waveform for realizing the example of the electric field waveform shown in FIG. In the example shown in FIG. 7, a high frequency waveform signal P1 having a period T equal to the asymmetric waveform electric field in FIG. 3 and pulse widths t1 and t2 is supplied to the first electrode 121, A high frequency waveform signal P2 having widths t1 and t2 is supplied to the second electrode 122 . The amplitude of the high frequency waveform signal P1 is Vmin/2 to -Vmax/2, and the amplitude of the high frequency waveform signal P2 is Vmax/2 to -Vmin/2. An example of the electric field waveform shown in FIG. 3 can also be realized by using such an asymmetrical voltage waveform signal.

(Second embodiment)
Next, a second embodiment will be described. The second embodiment differs from the first embodiment mainly in the configuration of the ground electrode. FIG. 8 is a cross-sectional view showing the ionizer, ion filter, and ion detection electrodes in the second embodiment.

As shown in FIG. 8, the ground electrode 112 is provided inside the first opening 151 and the second opening 152 in the second embodiment. A gap exists between the ground electrode 112 and the inner wall of the first opening 151 , and a gap also exists between the ground electrode 112 and the inner wall of the second opening 152 .

Other configurations are the same as those of the first embodiment.

Effects similar to those of the first embodiment can also be obtained by the second embodiment.

Note that the ground electrode 112 may be provided inside the second opening 152 and not inside the first opening 151 .

(Third embodiment)
Next, a third embodiment will be described. The third embodiment differs from the first embodiment mainly in the configuration of the ion filter. FIG. 9 is a cross-sectional view showing the ionizer, ion filter and ion detection electrodes in the third embodiment.

As shown in FIG. 9, in the third embodiment, an ion filter 120 is provided on an SOI (silicon on insulator) substrate 310 . The SOI substrate 310 has a support layer 320 , an insulating layer 330 and an active layer 340 . An insulating layer 330 is formed over the support layer 320 and an active layer 340 is formed over the insulating layer 330 . The support layer 320 is, for example, a conductive silicon substrate. The insulating layer 330 is, for example, a silicon oxide layer. The active layer 340 is, for example, a silicon layer with a conductive layer, and the ion filter 120 is formed on the active layer 340 . SOI substrate 310 is an example of a laminate.

A third opening 153 communicating with the first opening 151 is formed in the insulating layer 330 , and a fourth opening 154 communicating with the third opening 153 is formed in the supporting layer 320 . A fifth opening 155 communicating with the gap between the first electrode 121 and the second electrode 122 is formed in the insulating layer 330, and a sixth opening 156 communicating with the fifth opening 155 is formed in the support layer 320. there is The third opening 153 and the fourth opening 154 are examples of the guiding portion.

The ground electrode 112 is provided inside the first opening 151 , the third opening 153 and the fourth opening 154 . A gap exists between the ground electrode 112 and the inner wall of the first opening 151 , a gap exists between the ground electrode 112 and the inner wall of the third opening 153 , and a gap exists between the ground electrode 112 and the inner wall of the fourth opening 154 . A gap exists between them.

In the SOI substrate 310, for example, part or all of the region 113 where NO _x and NO _x ^- are concentrated is located inside the fourth opening 154, and part of the region 114 where OH ^- is concentrated. Alternatively, they are arranged so that they are all positioned inside the sixth opening 156 .

Other configurations are the same as those of the first embodiment.

Effects similar to those of the first embodiment can also be obtained by the third embodiment. In addition, the support layer 320 facilitates separation of NO _x ^- and NO _x from OH ^- from each other. Therefore, it is possible to make it more difficult for NO _x ⁻ to reach the ion detection electrode 130, and it is possible to make it more difficult for NO _x and OH ⁻ to mix. Therefore, detection sensitivity can be further improved.

It is preferable to apply a constant voltage to the support layer 320 when measuring the gas molecules to be detected. By applying a constant voltage to the support layer 320 , the ionized sample gas can be easily guided to the gap between the first electrode 121 and the second electrode 122 .

A ground electrode 112 may be provided inside the first opening 151 , the second opening 152 , the third opening 153 and the fourth opening 154 .

(Fourth embodiment)
Next, a fourth embodiment will be described. The fourth embodiment differs from the third embodiment mainly in the configuration of the ground electrode. FIG. 10 is a cross-sectional view showing the ionizer, ion filter and ion detection electrodes in the fourth embodiment.

As shown in FIG. 10, in the fourth embodiment, the insulating layer 330 has an electrode supporting portion 331. As shown in FIG. The electrode support portion 331 is provided inside the third opening 153 . The ground electrode 112 is supported by the electrode support portion 331 and provided inside the fourth opening 154 . A gap exists between the electrode supporting portion 331 and the inner wall of the third opening 153 , and a gap exists between the ground electrode 112 and the inner wall of the fourth opening 154 .

Other configurations are the same as those of the third embodiment.

Effects similar to those of the third embodiment can also be obtained by the fourth embodiment.

(Fifth embodiment)
Next, a fifth embodiment will be described. A fifth embodiment relates to a toilet apparatus equipped with a gas analyzer. FIG. 11 is a cross-sectional view showing a toilet device according to a fifth embodiment.

The toilet apparatus 200 according to the fifth embodiment has a toilet body 210, a control panel 230, and a toilet seat 240, as shown in FIG. A toilet seat 240 is placed on the toilet body 210 .

The toilet body 210 has a first toilet bowl portion 211 for stool, a second toilet bowl portion 212 for urination, and a wall portion 213 that separates the first toilet bowl portion 211 and the second toilet bowl portion 212 . A toilet drainage channel 216 for feces is connected to the bottom of the first toilet bowl 211 , and a toilet drainage channel 218 for urine is connected to the bottom of the second toilet bowl 212 . The toilet drainage channels 216 and 218 are connected to each other at a junction 219 provided at the bottom of the toilet body 210 .

The toilet drainage channel 216 has a U-shaped sealed water storage portion v15 between the confluence portion 219 and the bottom of the first toilet bowl portion 211, and the toilet drainage channel 218 has the confluence portion 219 and the second toilet bowl portion. It has a U-shaped sealed water reservoir 217 between it and the bottom of 212 . Sealed water is stored in each of the sealed water reservoirs 215 and 217 . The toilet drainage channel 216 further has a holding portion 214 that is provided between the sealed water storage portion 215 and the bottom portion of the first toilet bowl portion 211 and holds stool. The holding part 214 has, for example, a horizontal surface 214A facing vertically upward and extends in the horizontal direction. The holding portion 214 may have a surface substantially parallel to the seat surface of the toilet seat 240, for example. The holding part 214 may have a surface substantially parallel to the opening leading to the first toilet bowl part 211 of the toilet drainage channel 216, for example.

The toilet body 210 has a cleaning liquid nozzle 221 near the upper end of the first toilet bowl 211 for discharging a cleaning liquid such as water for cleaning the inner surface of the first toilet bowl 211 , and near the upper end of the second toilet bowl 212 . , there is a cleaning liquid nozzle 222 for discharging cleaning liquid such as water for cleaning the inner surface of the second toilet bowl 212 .

The control panel 230 includes an aspirator 231 , an analyzer 232 , an output device 233 and a controller 234 .

A movable suction head 220 is connected to the suction device 231 via a tube 223 . The suction head 220 is movable, for example, between a first position above the rim of the toilet body 210 and a second position near the center of the upper end of the first toilet bowl part 211 .

The analysis device 232 analyzes the composition of the gas sucked by the suction device 231 . The analysis device 232 includes a detection device according to any one of the first to fourth embodiments.

The output device 233 outputs the results of analysis by the analysis device 232 . The output device 233 includes, for example, a display device. The output device may store the output results in a storage medium, or transmit the analysis results to an external device through wireless or wired communication.

The control device 234 controls the suction device 231 , the analysis device 232 and the output device 233 .

When defecation is performed using the toilet device 200, feces and urine are guided to the first toilet bowl 211 for feces and the second toilet bowl 212 for urine separated by the wall 213, respectively. It should be noted that the suction head 220 is placed at the first position above the rim of the toilet body 210 when defecation. Urine guided to the second toilet bowl 212 falls along the inner surface of the second toilet bowl 212 to the sealed water reservoir 217 . On the other hand, stool guided to the first toilet bowl 211 falls along the inner surface of the first toilet bowl 211, but is held on the horizontal surface 214A of the holding part 214 before reaching the water seal reservoir 215. . Then, the gas emitted from the stool held in the holding portion 214 diffuses into the first toilet bowl portion 211 .

When the control device 234 is operated in a state where the gas emitted from the stool is diffused in the first toilet bowl 211, the suction head 220 is moved to the second position near the center of the upper end of the first toilet bowl 211, The suction device 231 starts sucking gas. That is, the suction device 231 sucks the gas emitted from stool and diffused in the first toilet bowl 211 via the suction head 220 and the tube 223 . Then, the analysis device 232 analyzes the gas contained in the gas sucked by the suction device 231 , and the output device 233 outputs the result of the analysis by the analysis device 232 . When the analysis by the analyzer 232 is finished, the suction of the gas by the suction device 231 is finished, and the suction head 220 is moved to the first position. The analyzer 232 analyzes, for example, the concentration of chemical substances such as ammonia contained in the gas.

After that, by discharging water from the washing liquid nozzle 221 , the first toilet bowl 211 is washed, and stool is guided to the sealed water reservoir 215 and discharged to the outside from the confluence 219 . Further, by discharging water from the washing liquid nozzle 222 , the second toilet bowl portion 212 is washed, and urine is discharged from the confluence portion 219 to the outside.

According to the fifth embodiment, gas emitted from stool can be analyzed without being affected by gas emitted from urine. Further, even if the first toilet bowl portion 211 and the second toilet bowl portion 212 are separated, when trying to analyze the gas emitted from the stool when the stool has fallen into the sealed water, The gas dissolves into the sealing water, or the gas emitted from the sealing water mixes. Therefore, when stool is dropped into the sealed water, it is difficult to analyze the gas emitted from the stool with high accuracy. On the other hand, in the fifth embodiment, the suction by the suction device 231 and the analysis by the analysis device 232 are performed while the stool is held in the holding section 214 . Therefore, according to the fifth embodiment, the gas emitted from stool can be analyzed with high accuracy while suppressing the influence of sealed water. That is, the gas emitted from stool can be collected and analyzed with high accuracy while suppressing changes in the component ratio and concentration. By using this analysis result, it is possible to manage the physical condition of the subject with high precision and contribute to the early detection of disease. Analyzer 232 is an example of a gas analyzer.

Although the preferred embodiments and the like have been described in detail above, the present invention is not limited to the above-described embodiments and the like, and various modifications can be made to the above-described embodiments and the like without departing from the scope of the claims. Modifications and substitutions can be made.

100 detection device 110 ionizer 111 discharge needle 112 ground electrode 120 ion filter 121 first electrode 122 second electrode 130 ion detection electrode 150 discharge part 151 first opening 152 second opening 161 ion current detection circuit 200 toilet device 232 analyzer

Patent No. 5822292

Claims (14)

an ionization unit that ionizes gas by corona discharge;
an ion filter that selectively transmits a part of the ions ionized by the ionization unit;
an ion detection electrode on which ions that have been ionized by the ionization unit and passed through the ion filter collide;
a discharge unit that selectively discharges a part of the ions generated by the corona discharge;
A detection device comprising: The discharge unit is
a first exhaust port formed in the ion filter;
a second exhaust port formed in the exhaust portion and communicating with the first exhaust port;
The detection device according to claim 1, characterized by comprising: The ionization unit is
a discharge needle;
a ground electrode provided inside the first exhaust port;
3. The detection device according to claim 2, characterized by comprising: 4. The detection device according to claim 2, further comprising a guide section that guides ions discharged from the discharge section to the first exhaust port. a laminate comprising a supporting layer, an insulating layer formed on the supporting layer, and an active layer formed on the insulating layer;
the guide portion is formed on the support layer and the insulating layer;
5. The detection device according to claim 4, wherein said ion filter is formed in said active layer. 6. The detection device according to claim 5, wherein said laminate is a silicon-on-insulator substrate having said active layer as a silicon layer. The ionization unit is
a discharge needle;
a ground electrode provided closer to the ion filter than the discharge needle;
3. The detection device according to claim 1 or 2, characterized by comprising: 1. The ion filter has a first electrode and a second electrode facing each other, and controls the mobility of ions passing between the first electrode and the second electrode. 8. The detection device according to any one of 7. 9. The detection device according to any one of claims 1 to 8, wherein the ions discharged from the discharge part are NO _x ^- . 10. The detection device according to claim 9, wherein molecules of _NOx generated by the corona discharge are also discharged from the discharge part. A gas analyzer provided in a toilet bowl,
11. A gas analyzer comprising the detection device according to any one of claims 1 to 10, wherein the gas emitted from stool is used as the gas and the gas emitted from stool is analyzed. an ionization unit that ionizes gas by corona discharge;
an ion filter that selectively transmits a part of the ions ionized by the ionization unit;
an ion detection electrode on which ions that have been ionized by the ionization unit and passed through the ion filter collide;
A method of using a detection device comprising:
generating corona discharge by the ionization unit without supplying the gas;
a step of selectively discharging some of the ions generated by the corona discharge;
a step of colliding other part of the ions generated by the corona discharge with the ion detection electrode through the ion filter;
detecting current generated in the ion detection electrode using an ion current detection circuit connected to the ion detection electrode;
adjusting the setting of the ion current detection circuit according to the result of detection by the ion current detection circuit;
A method of using a detection device comprising: 13. The method of claim 12, wherein the ejected ions are NO _x ^- . 14. A method of using a detection device according to claim 13, further comprising the step of discharging molecules of NO _x generated by said corona discharge together with said NO _x ^- .

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