TECHNICAL FIELD
5 The present invention relates to a chip for measuring number of microbe, and to an
apparatus for measuring number of microbe in which this chip is used.
BACKGROUND ART
A conventional chip for measuring number of microbe was configured as follows.
With a conventional chip for measuring number of microbe, for example, microbes
10 were collected using a cotton swab or other such microbe collection tool from inside the oral
cavity, and this microbe collection tool was immersed in a liquid in a container from an
opening in the upper face of the container. After this, the liquid in the container was stirred
with a stirrer, and in this state the microbe count was measured with a measuring electrode
provided inside the container (see Patent Literature 1, for example).
15 CITATION LIST
PATENT LITERATURE
Patent Literature l: Japanese Laid-Open Patent Application 2010-220507
SUMMARY
TECHNICAL PROBLEM
20 With the above-mentioned conventional configuration, elution and measurement of
the microbes can be performed in the container, which was considered an advantage because
the size of the device itself could be extremely small.
n
A
However, a measuring electrode has to be integrally provided to the inner wall surface
of the container used to perform such measurements. Moreover, the takeoff leads from this
measuring electrode to the outside of the container have to be made watertight somehow,
which drives up the production cost.
Therefore, it ends up being expensive to take a microbe count when this container is
used.
In view of this, it is an object of the present invention to provide a chip for measuring
number of microbe with which measurement costs can be cut.
SOLUTION TO PROBLEM
To achieve the stated object, the chip for measuring number of microbe of the present
invention comprises a chip main body in the form of a long plate, a measuring electrode, a
connecting electrode, a ground electrode, and a conductive pattem. The measuring electrode
is provided on a first end side in the longitudinal direction of the surface of the chip main
body, and is immersed in a measurement liquid. The connecting electrode is corurected to the
measuring electrode and is provided on a second end side on the opposite side from the first
end in the longitudinal direction of the surface of the chip main body. The ground electrode
is provided on the second end side of the surface of the chip main body. The conductive
pattern is connected to the ground electrode and is provided to the outer peripheral portion of
the measuring electrode
The apparatus for measuring number of microbe of the present invention makes use of
the above-mentioned chip for measuring number of microbe, and comprises a container
holder, a rotary driver, an electrode insertion portion, and a measurement section. The
10
15
n
20
2
n
container holder holds a bottomed cylindrical container having an opening in its upper face,
with the opening facing up. The rotary driver rotates the container held in the container
holder along with a liquid stored inside, around the central axis of the container running in a
substantially vertical direction. The elechode insertion portion inserts the chip for measuring
number of microbe through the opening in the container held in the container holder, at a
position inside the container that is closer to the inner wall side than the central axis, and a
position that is a specific distance away from the inner wall surface. The measurement
section measures microbes at the measurement electrode of the chip for measuring number of
microbe inserted into the container by the electrode insertion portion.
Furthermore, the chip for measuring number of microbe of the present invention
comprises a chip main body in the form of a long plate, a measuring electrode, a connecting
electrode, a connector, and a cover. The measuring electrode is provided on the lower end
side of the surface of the chip main body, is immersed in a measurement liquid, and has
mutually opposing fust and second measuring electrodes on the lower end side of the surface
of the chip main body. The connecting electrode is provided on the upper end side of the
surface of the chip main body, is connected to a measurement device, and has first and
second connecting electrodes. The connector connects the measuring electrode and the
connecting electrode at the surface of the chip main body, and has a first connector where the
first measuring electrode and the first connecting electrode are corulected between the upper
and lower ends of the surface of the chip main body, and a second connector where the
second measuring electrode and the second connecting electrode are connected between the
upper and lower ends of the surface of the chip main body. The cover is provided so as to
10
15 n
20
cover the surface of the first and second connectors between the upper and lower ends of the
surface of the chip main body.
ADVANTAGEOUS EFFECTS
With the chip for measuring number of microbe of the present invention, a container
having a simple bottomed cylindrical shape with an opening in its upper face can be used as
the container, which means that the production cost of the container can be lowered, and
measurement costs reduced.
Furthermore, with a conventional chip for measuring number of microbe, when the n
microbe count is taken, the user holds the chip for measuring number of microbe in his
10 fingers and inserts it into the electrode insertion portion of the device, but sometimes the user
would accidentally touch the measuring electrode on the chip for measuring number of
microbe, and the measuring electrode ended up being damaged by static electricity from the
user when being inserted into the device.
With the chip for measuring number of microbe of,the present invention, since the
conductive pattern is provided around the periphery of the measuring electrode, if the user
accidentally touches the measuring electrode, he will also touch the conductive pattem at the
same time, and static electricity from the user will flow through the conductive pattern to the
device side. This prevents the measuring electrode from being damaged by static electricity.
As a result, the user need not worry about the position where he holds the chip for measuring
number of microbe (the position where he grasps the chip for measuring number of microbe),
and this makes the chip for measuring number of microbe easier to handle.
l5
A
20
4
n
With the chip for measuring number of microbe of the present invention, when the
measuring electrode is immersed in a measurement liquid in order to take a microbe count,
the lower parts of the first and second connectors connected to the measuring electrode are
also immersed in the measurement liquid. Accordingly, when a specific voltage is applied to
the measuring electrode during measurement, voltage is also applied to the immersed part of
the connectors, and the immersed part has an impedance component. Furthermore, when the
measurement liquid is rotated around the center axis of the container during measurement, the
surface of the measurement liquid is shaken in the vertical direction, causing the immersed
part of the connectors to fluctuate. This fluctuation creates variance in the impedance
component of the immersed part, and variance occurs in the measurement value obtained
when measurement was performed at avaryingimpedance. This results in lower
measurement accuracy.
In view of this, with the chip for measuring number of microbe of the present
invention, a cover that covers the surface of the first and second connectors is provided
between the upper and lower ends of the surface of the chip main body, so the first and
second connectors do not touch the surface of the measurement liquid, and no variance in the
impedance component occurs in the first and second connectors. As a result, there is no
variance in the measurement value, so measurement accuracy can be improved.
BRIEF DESCRIPTION OF DRAWINGS
FIG. I is an oblique view of the apparatus for measuring number of microbe
pertaining to an embodiment of the present invention;
10
l5
,A20
FIG. 2 is an oblique view of the operating state of the apparatus for measuring number
of microbe in FIG. l'
FIG. 3 is a cross section of the operating state of the apparatus for measuring number
of microbe in FIG. l;
5 FIG. 4 is an oblique view of a container in the apparatus for measuring number of
microbe in FIG. l;
FIGS. 5a to 5c are front views of the measurement chip and the constituent members
n thereof in the apparatus for measuring number of microbe i FIG. 1;
FIG. 6 is a cross section of the operating state of the apparatus for measuring number
l0 of microbe in FIG. l;
FIG. 7 is a control block diagram of the apparatus for measuring number of microbe
in FIG. l;
FIG. 8 is a top view of the container of the apparatus for measuring number of
microbe in FIG. l;
15 FIG. 9 is a cross section of the liquid flow inside the container of the apparatus for
^ measuring number of microbe in FIG. l;
FIGS. 10a and l0b are front views of the measurement chip during operation of the
apparatus for measuring number of microbe in FIG. l;
FIGS. I la and l lb are configuration diagrams of connection terminals of the
20 apparatus for measuring number of microbe in FIG. l; and
FIG. 12 shows the connection relation between the measurement chip and the
apparatus for measuring number of microbe in FIG. 1.
6
a
DESCRIPTION OF EMBODIMENTS
Embodiment I
The measurement chip (chip for measuring number of microbe) 15 and apparatus for
measuring number of microbe pertaining to an embodiment of the present invention will now
be described through reference to the drawings.
As shown in FIG. 1, the apparatus for measuring number of microbe in this
embodiment comprises a box-shaped main body case I and a front cover 2 provided openably
upward at the front (see FIG. 2).
As shown in FIG. 2, acontainer holder 3 that has opening at the top and holds a
container 4 is provided to the rear side of the front cover 2 on the inside of the main body
case 1.
As shown in FIGS. 3 and 4, the container 4 is in the form of a bottomed cylinder
having a circular opening at the top, and is held in the container holder 3 with the opening
facing up. A cylindrical holder 5 is forrned on the bottom face of the container 4. Three
elution protrusions 6 are formed substantially vertically in the iru-rer side face of the holder 5
at intervals of 120 degrees in the peripheral direction. Three elution grooves 7 that pass
through from the inside to the outside are formed at intervals of 120 degrees in the side face
of the holder 5. Further, pure water 8 (an example of a measurement liquid) for eluting
microbes M (see FIG. 8) is held in the container 4.
As shown in FIG. 3, a collection portion 10 provided to the lower end of a rod-shaped
microbe collection tool 9 is inserted from above into the holder 5 of the container 4, and the
microbe collection tool 9 is held by the holder 5. The collection portion l0 of the microbe
l0
15
,A.
20
7
,^
, 10
collection tool 9 is inserted into an oral cavity, for example, to pick up saliva and collect the
microbes M.
ln this state, the user presses the switch I I in FIG. 2 with the left hand while grasping
the upper end portion of the microbe collection tool 9 with the right hand, for example. The
rotation of a motor 12 then causes the container holder 3 to rotate. Since drive protrusions
(not shown) of the container holder 3 are engaged with engagement protrusions (not shown)
of the container 4 at this point, the container 4 can be rotated. When the container 4 rotates,
the operation lamp 13 in FIG. 2 is lit. In this state, the container 4 rotates for a preset timer
time (such as 10 seconds).
This rotation causes the elution protrusions 6 provided to the inner wall face of the
holder 5 to hit the collection portion 10 of the microbe collection tool 9. Therefore, microbes
M inside the collection portion l0 are eluted through the elution grooves 7 into the pure water
8 in the container 4.
Upon completion of this elution operation, the user pulls the microbe collection tool 9
l5 upward out of the container 4.
The user then mounts the measwement chip 15 shown in FIG. 5c to a measurement
chip holder 14 provided to the inner face of the front cover 2.
As shown in FIG. 5a, the measurement chip 15 in this embodiment has a chip main
body l5A in the form of a long, thin plate, a measuring electrode 16, a connecting electrode
20 17, anda connector 18.
8
1
The measuring electrode 16 is provided on the lower end side (one end in the
longitudinal direction) of the surface of the chip main body 15A, and is immersed in the pure
water 8.
The connecting electrode 17 is provided on the upper end side (the other end in the
longitudinal direction) of the surface of the chip main body l5A, and is connected to the
measurement chip holder 14 of ameasurement device.
The connector 18 connects the measuring electrode 16 and the connecting electrode
17 atthe surface of the chip main body 15A.
In this embodiment, palladium is sputtered over PET (polyethylene terephthalate),
l0 which is used as the substrate of the chip main body l5A, and the palladium is worked with a
laser to fonn the measuring electrode 16, the connecting electrode 17, and the connector 18.
In addition to palladium (Pd), the metal material of the electrodes, etc., sputtered over
the PET or other substrate may be aluminum (Al), silver (Ag), gold (Au), copper (Cu), or
another such metal material.
The configuration of the measurement chip 15 will be described in detail at alater
point.
Next, the user grasps the approximate middle of the measurement chip 15 in FIG. 5,
and mounts the connecting electrode 17 to the measurement chip holder 14, whereupon an
electrical and mechanical connection is made between the measurement chip 15 and the
device as shown in FIG. 3. That is, in this embodiment, the electrode insertion portion is
constituted by the front cover 2,the measurement chip holder 14, etc.
t5
1
20
9
From this state, the front cover 2 is rotated forward with a handle 19, and when it has
been rotated to the state in FIG. 1, the measurement chip 15 is inserted into the container 4
via the opening in the container 4 from above the container 4 held in the container holder 3,
as shown in FIG. 6. The measuring electrode 16 of the measurement chip l5 at this point is
immersed in the pure water 8 in the container 4.
Next, the user presses a measurement start switch 20 (FIG. 1) to commence
measurement. A voltage of 3 MHz, for example, is applied to the measuring electrode 16,
and the microbes M eluted into the container 4 are gathered at the measuring electrode 16. At
the same time, a voltage of 800 kHz, for example, is applied to the measuring electrode 16,
and the impedance change of the measuring electrode 16 is measured to take a microbe count.
This measurement method is already known from prior publications and so forth, so it
will not be described here, to keep the description from being overly complicated.
In this embodiment, the configuration is such that the motor 12 rotates the container
holder 3, the container 4, and the pure water 8 during measurement, so that there are more
l5 oppornrnities for the microbes M that are widely diffused in the container 4 to approach the
A
measuring electrode I 6.
In a state in which a microbe count is being taken by the measurement chip 15, as
shown in FIG. 6, a rod-shaped manipul ator 22is inserted into a through-hole 21 (see.FIG. 5)
provided in the center of the measurement chip 15.
20 The manipulator 22 is retracted to the rear as shown in FIG. 3 until the measurement
chip 15 descends all the way in the container 4, but protrudes toward the front cover 2 as
l0
10
shown in FIG. 6 from immediately before the measurement chip 15 descends all the way in
the container 4.
The through-hole 21 is in the form of a slot that is longer in the longitudinal direction
of the measurement chip l5 (FIG. 5).
5 Therefore, when the user opens up the front cover 2 aftet measurement, the lower end
of the through-hole 21 in the measurement chip 15 engages with a hook-shaped engagement
component (not shown) provided to the distal end of the manipulatot 22- As a result' the
measurement chip 15 is separated from the measurement chip holder 14. Also, when the
front cover 2 is opened up, if the front cover 2 is pulled to the rear (the right side in FIG' 6) in
l0 a state in which the measurement chip 15 hasbeen separated from the measurement chip
holder 14, the distal end of the hook-shaped engagement component (not shown) provided to
themanipulatorZ2comesoutofthethrough-hole2linthemeasurementchipl5.
That is, the measurement chip 15 is pulted out of the measurement chip holder 14' and
remains inthe container 4 aftet measurement'
l5Accordingly,theopeningofthefrontcover2doesnotcausethepurewater8
,1
contarning the microbes M that have adhered during measurement to inadvertently be
splashedordrippedontothefrontorbottomfaces,etc',ofthefrontcover2'whichis
preferable in terms of cleanliness'
FIG. 7 is a control block diagram of the apparatus for measuring number of microbe
20 usedto carry outthe above operation'
Themotor12isconnectedtoamotorpowersupply24ofapowersupply23.
11
I
The motor power supply 24 is connected to a motor power supply controller 26 of the
controller 25.
An electrode power supply 27 of the power supply 23 is connected to the measuring
electrode 16.
5 The electrode power supply 27 is connected to an electrode power supply controller
28. Consequently, the above-mentioned voltages of 3 MHz and 800 Wlzare applied from the
electrode power supply 27 to themeasuring electrode 16, and a microbe count is taken at the
_ same time by a measurement section}g andcomputer 30 connected to the measuring
electrode 16. The measurement result is displayed on a display section 3l provided at the
l0 rear ofthe front cover 2.
An interface section 32 is used to operate the power supply. The switch 11 and
operation lamp 13 shown in FIG. 2,themeasurement start switch 20 in FIG. 1, and so forth
are all connected to a controller 25'
Specifically, with the apparatus for measuring number of microbe in this embodiment,
l5 an electrode insertion portion (made up of the front cover 2,the measurement chip holder 14'
'^ etc.) is provided for inserting the measurement chip 15 into the container 4 through the
opening in the container 4 from above the container 4 held in the container holder 3'
Therefore, the container 4 can have a simple bottomed cylindrical shape having a circular
opening in its upper face. As a result, the cost of producing the container 4 is lower than in
20 the past, and measurement costs can be reduced'
Next, the relation between the pure water 8 and the measurement chip 15 during the
microbe count will be described.
12
As shown in FIG. 8, during measurement the measurement chip l5 is disposed at a
position closer to the inner wall of the container 4 than the center axis of the cylindrical
container 4, and at a position that is close to the inner wall of the container 4. The measuring
electrode 16 of the measurement chip 15 is disposed opposite the inner wall of the container 4.
In this state, when the cylindrical container 4 rotates around the center axis of the
cylinder, as shown in FIG. 9, an eddy-like swirl flow is generated around the center axis
running in the vertical direction in the pure water 8, and the outer peripheral portion of this
swirl flow rises up to the position A in the drawing. To facilitate an understanding of this
point, the holder 5 is not depicted in FIG. 9. Also, we shall assume that the level of the pure
water 8 is at the position B in the drawing when the container 4 is not rotating'
Since the measurement chip 15 is disposed at a position close to the inner face of the
container 4, surface tension forms a butging portion of the pure water 8 (as shown in FIG' 9)
in the portion surrounded by the measurement chip 15 and the inner wall of the container 4'
This results in a state in which the measuring electrode 16 is reliably submelged in the pure
water 8.
As shown in FIG. g, the swirl flow in the container 4 subjects the microbes M
contained in the pure water 8 to centrifugal force, and causes them to swirl along the inner
wall of the container 4 trt astate of being biased toward the inner wall of the container 4 '
Consequently, the microbes M swirling along the inner watl of the container 4 can be caught
bythemeasuringelectrodel6,whichisdisposedoppositetheinnerwallofthecontainer4.
Measuring Electrode 16
l0
15
20
13
l0
Next, the con{iguration of the measurement chip 15 will be described in detail through
reference to FIGS. 5a to 5c.
The measurement chip 15 in this embodiment, as discussed above, comprises the
measuring electrode 16, the connecting electrode 17, andthe connector 18.
As shown in FIG. 5a, the measuring electrode 16 has two measuring electrodes 164
and 168, which are opposite each other and separated by a specific gaP, on the lower end side
of the surface of the chip main body 15A. Because the measuring electrodes 164 and 16B
are spaced apart by a specific gap, this forms a comb electrode 16C.
The connecting electro de 17 has two connecting electrodes 17A and 17B on the upper
end side of the chiP main bodY l5A.
The connector 1g has a connector 18A that connects the measuring electrode 164 and
the connecting electrod e lTAbetween the upper and lower ends of the surface of the chip
main body 15A, and a connector 18B that connects the measuring electrode 16B and the
connecting electrode I 7B.
The measurement chip 15 in this embodiment further comprises a cover 33 (see FIG'
5b) provided in order to cover the surface of the connectors 18A and 18B between the upper
and lower ends of the surface of the chip main body 15A shown in FIG' 5a'
As shown in FIG. 10b, the cover 33 is in the form of a long, thin plate, and covers
substantially the entire surface of the connectors l8A and 188. The cover 33 is formed from
PET,justasthechipmainbodyl5Ais.Thethicknessofthecovef33isthesameasthe
thickness of the chip main body 15A''
This affords higher mqNurement accuracy of the meursurement chip 15'
l5
20
l4
Specifically, as shown in FIGS. 6 and 9, the measurement chip 15 is inserted into the
container 4 through the opening in the container 4 from above the container 4 held in the
container holder 3. The measgring electrode 16 of the measurement chip l5 here is immersed
in the pure water 8 in the container 4. The lower part of the connector 18 connected to the
5 measuring electrode 16 is also immersed in the measurement liquid at this point. Therefore,
when voltage is applied to the measuring electrode 16 at the start of measurement, voltage is
also applied to this immersed part, and the immersed part has an impedance component'
When the pure water 8 is furttrer rotated around the center axis of the container 4 for
^
meas*rement, as shown in FIG. l0a, the surface of the pure water 8 is shaken by an amount
10 Ll in the vertical direction, carsing the immersed part of the connector 18 to fluctuate' This
fluctuation creates variance in the impedance component of the immersed part'
The measuring electrode 16 performs measurement by a change in impedance' so
varianceintheimpedancecomponentoftheconnectorlScreatesvarianceinthe
measurement value'
15 In view of this, in this embodiment, as discussed above, the cover 33 for covering the
.surfaceoftheconnectorsl8Aandl88isprovidedbetweentheupperandlowerendsofthe
surface of the chip main body l5A' as shown in FIG' 10b'
consequently, the connectors 18A and l88 do not touch the surface of the pure water
g (hat is, the shake amount Ll in the vertical direction of the liquid surface), so the
20 connectors lgA and 1gB do not have an impedance component. Therefore, no variance of
the impedance component occurs in the connectors l8A and 188'
15
As a result, there is no variance in the meznurement value, which means the
measurement accuracy is higher.
In FIG. l0b, the connectors 18A and l8B are seen below the center of the lower end
of the cover 33, and this seen part is lower than the shake amount Ll of the liquid surface'
That is, the connectors l8A and 18B are parts that are always immersed in the pure water 8'
Therefore, these parts are immersed and have an impedance component' but because they are
always immersed, there is no variance in the impedance component'
AsshowninFlG.6,thethrough-hole2lprovidedinthecenterportionofthechip
main body l5A is located above the container 4 during measurement, so the liquid level does
not reach the through-hole 21. That is, as shown in FIG. 10, the configuration is such that the
shakeamountLlofthetiquidlevelisproducedontheconnectorlsbetweenthemeasuring
electrode l6 and the through-hole 21'
Furthermore, in this embodiment, as shown in FIG' l0a' it is assumed that the size of
the connectors 1gA and 1gB in the short-side direction (the width direction) is substantially
the same, and is substantially one-half the width of the chip main body 154'
Therefore, the impedance component (the direct resistance component) of the
connectorlScanbereduced,andmeasurementsensitivitycanbeincreasedinmeasurement
by the measuring electrode 16, which measures the microbe count from minute changes in
impedance.
This point will be described in some firther detail'
l0
15
20
16
I
To accurately ascertain the change in impedance at the measuring electrode 16 (that is,
a change in the microbe count), the impedance component (the direct resistance component)
of the connector 18 must be reduced.
Ways to reduce the impedance component (the direct resistance component) of the
5 connector 18 include
(1) shortening the length of the connector l8 or
(2) increasing the size of the connector 18 in its short-side direction (width direction),
amons other methods'
However, a problem with method (1) is that it is difficult to reduce the length of the
10 connector 1g more than a certain amount because the measuring electrode 16 must be
immersed in the Pure water 8'l
Meanwhile, with method (2), the impedance component of the connector 18 itself
does decrease when the connector 18 is made smaller in its short-side direction (width
direction), but the connector 18A and connector 18B that make up the connector l8 end up
15 being next to each other at a very close spacing. Therefore, a new impedance component is
'^ created between the immersed connector 18A and connector 18B at the portion of the
connector 1g that is immersed in the pure water 8. The size of this impedance component is
inversely proportional to the distance by which the connector l8A and connector l88 are
seParated.
20 That is, if the size of the connector 18 is increased in its short-side direction (width
direction) in an attempt to reduce the impedance component of the connector 18, the
connectors 1gA and lgB will be spaced closer together. AccordinglY, the impedance
17
l0
component generated between the immersed connector 18A and connector l8B ends up being
greater.
In this embodiment, however, the cover 33 is provided to cover the surface of the
connectors 18A and l8B as discussed above. Therefore, the connectors 18A and 188 are not
immersed in the pure water 8, and no new impedance component is generated between the
connector 18A and the connector 188.
Accordingly, the size of the connectors l8A and l8B in the short-side direction (width
direction) is substantially the same, and the impedance component (direct resistance
component) of the connector 18 can be reduced by increasing the size to substantially onehatf
the size of the chip main body 15A in the short-side direction (width direction). This
affords better measurement sensitivity of the measuring electrode 16.
Furthermore, in this embodiment, as shown in FIGS. lOa and l0b, the measuring
electrodes 164 and 168 form the comb electrode l6C where they are opposite each other at a
specific spacing. The comb electrode 16C is in the form of a rectangle that is longer in the
longitudinal direction of the chip main body 15A, and is disposed in the center of the chip
main body l5A in its short-side direction (width direction), on the lower end side of the
surface of the chip main body l5A.
This is because the distance from the comb electrode 16C to the long side of the chip
main body 154 opposite the comb electrode l6C is increased in the short-side direction
(width direction) of the chip main body 15A. Consequently, the surface area of the two parts
16a and 16b sandwiched betweenthe comb electrode l6C and tt
"
lor,g side of the chip main
l5
20
18
10
body 154. can be increased, and the impedance component (direct resistance component) of
theparts 16aand l6b canbereduced.
As a result, the impedance component (direct resistance component) of the measuring
electrodes 164 and 168 of the measuring electrode 16 can be reduced, and measurement
sensitivity can be improved in this respect as well.
Furthermore, in this embodiment, as shown in FIG. 10b, the cover 33 is in the form of
a long plate, and the lower end center thereof is disposed more toward the upper end side of
the chip main body l54 than the comb electrode l6C of the measuring electrode 16 of the
chip main body l5A. Also, the lower end center of the cover 33 is disposed more toward the
lower end side than the shake amount Ll of the liquid level in the vertical direction caused by
rotation of the pure water 8.
Accordingly, the lower end center of the cover 33 is reliably immersed in the pure
water 8. Therefore, the connectors 1 8A and I 8B covered by the cover 33 do not touch the
pure water 8, so no variance occurs in the impedance component of the connectors 18A and
188. This results in higher measurement accuracy'
Furthermore, in this embodiment, extensions 33A and 33B are formed by extending
both sides of the cover 33 on the lower end side to the lower end of the chip main body l5A'
The two extensions 33A and 33B do not cover the comb electrode 16C of the measuring
electrode l6 immersed in the pure water 8'
Accordingly, the comb electrode l6C of the measuring electrode 16 can be reliably
brought into contact with the pure water 8, and the area around the comb electrode 16C can
be reinforced by the extensions 33A and 33B. Therefore, rotation of the pure water 8 does
l5
20
t9
not cause problems such as shaking of the measuring electrode 16 provided over the chip
main body 154, which is in the form of athin, long plate, so the measurement can be carried
out while the comb electrode l6C of the measuring electrode 16 is in a stable state. This also
enhances measurement accuracY.
5 As shown in FIG. 5a, in this embodiment, a slot-form through-hole2lAis provided to
the middle part of the chip main body l54 in order to separate it from the measurement
device to which the chip main body l5A is mounted'
Also, as shown in FIG. 5b, the upper end of the cover 33 is disposed more on the
upper encl side of the chip main body l5A than the through-hole 2lA of the chip main body
l0 l5A. Furttrer, a through-hole 21B that has the same shape as the through-hole 21A is
provided to the portion of the cover 33 corresponding to the through-hole 2lA of the chip
main body l5A. That is, the through-hole 2lA and the through-hole 21B form the throughhole
2l as shown in FIG. 5c-
This makes the device easier to use for the user'
15 Specifically, the user opens up the front cover 2 once the measurement is complete,
but as discussed above, the through-hole 21 is provided so that the measurement chip 15 will
be pulled out of the measurement chip holder 14 in conjunction with this opening operation,
in order to separate it into the container 4'
As shown in FIG. 5, the through-hole 2l is formed in the center portion of the
20 measurement chip l5 (in the form of a long, thin plate) and is in the form of a slot in the
longitudinal direction of the measurement chip 15. Accordingly, the portion around the
through-hole 21 is weaker than the middle of the measurement chip 15. In view of this, the
20
portion around the through-hole 21 is reinforced by disposing the upper end of the cover 33
closer to the upper end side of the chip main body l5A than the through-hole 21A of the chip
main body l5A.
As discussed above, the cover 33 is similar to the chip main body 15,{ in that it is
5 formed from PET, and has the same thickness as the chip main body l5A. Thus, the cover 33
has substantially the same strength as the chip main body l5A.
Consequently, during measurement, the user grasps the measurement chip 15
somewhere in its middle, and mounts the connecting electrode 17 to the measurement chip
holder 14 (see FIG. 2), but since the portion around the through-hole 21 is reinforced by the
l0 cover 33, the measurement chip 15 is adequately strong for stable connection to be
accomplished. This makes the device easier to use for the user, and also improves
measurement accuracY.
Main Features
Conductive Patterns 34A,348, and 34C
, ,t The basic configuration and operation in this embodiment will be understood from the
As shown in FIG. 54 ground electrodes 37A and 378 are provided at the upper end of
the measurement chip l5 in this embodiment, on the outer peripheral side of the connecting
electrodes 17A and l7B.
20 Conductive patterns 34A and 34B are provided from the ground electrodes 37A and
37B toward the measuring electrode 16 at the lower end'
2l
The conductive patterns 34A and 34B extend from the ground electrodes 37A and
37B along the outer peripheral portion in the longitudinal direction of the measurement chip
15, and are each connected to a conductive paffern 34C.
That is, the conductive patterns 34A and 34B go past the outer peripheral side of the
5 connectors l8A and 188, respectively, and then are connected to the conductive pattem 34C
in a state of being provided around the outer periphery of the measuring electrodes l64 and
l68.
As a result, as shown in FIG. 5a, since the conductive patterns 34A and 34B are
provided around the outer periphery of the chip main body l5^A in the form of a long plate,
10 the outer periphery of the measuring electrode l6 is surrounded at the lower end of the chip
main body l5A.
As described above, the measurement chip l5 is used in a state in which the chip main
body 15,{ on shown in FIG. 5a is covered by the cover member 33 shown in FIG. 5b.
In a state in which the cover member 33 covers the chip main body 154, as shown in
l5 FIG. 5c, the conductive pattem 34C is provided around the outer periphery of the comb
electrode 16C at the lower end of the comb electrode l6C of the measuring electrode 16 that
is not covered by the cover 33.
As discussed above, an electrical and mechanical connection is made when the user
grasps and inserts the measurement chip 15 in FIG. 5 to mount the main body case
20 connecting electrode 17 to the measurement chip holder 14. FIG. l la shows the
configuration of connection terminals 35A and 35B of the electrode insertion portion
provided to the measurement chip holder 14.
22
l0
As shown in FIG. I la, the connection terminals 35A and 35B of the electrode
insertion portion provided to the measurement chip holder 14 arc respectively connected to
the connecting electrodes 17A and l7B of the measurement chip 15. Ground terminals 36,{
and 368 provided to both sides of these connection terminals 35A and 35B are connected to
the ground electrodes 37A and 37B provided to the measurement chip 15.
Of these, the ground terminal 368 is provided so as to be longer than the other
connection terminals 35A and 358 and the ground terminal 36,4..
Therefore, in the mounting of the measurement chip 15 to the connection terminals
35A and 35B of the electrode insertion portion, the ground terminal 368 is mounted to the
ground electrode 37B of the measurement chip 15 first. Accordingly, the ground electrodes
37A and 37B of the measurement chip l5 are connected to the ground potential on the device
side prior to the measuring electrode 16.
Therefore, damage to the measuring electrode 16 of the measurement chip 15 by static
electricity from the user can be prevented in the mounting of the measurement chip 15 to the
connection terminals 35A and 35B of the electrode insertion portion.
Specifically, with a conventional configuration, when the user holds the measurement
chip in his fingers and inserts it into the electrode insertion portion of the measurement chip
holder of the device in the taking of a microbe count, if the user's fingers should accidentally
touch the cornb electrode of the measuring electrode of the measurement chip, static
2A electricity from the user can damage the comb electrode of the measuring electrode.
In view of this, with the measurement chip 15 in this embodiment, as discussed above,
the conductive patterns 34A, 34B, and 34C, which are oonnected to the ground terminals 364
l5
ZJ
A
and 368 that serve as the ground potential of the device, are provided at the lower end of the
measuring electrode l6 (although, in this embodiment, just the conductive pattern 34C is
exposed from the cover member 33). This prevents the comb electrode 16C of the measuring
electrode 16 from being damaged by static electricity from the user.
This point will now be described in greater detail. In this embodiment, the
configuration is such that the conductive pattern 34C serves as the ground potential on the
device side prior to the measuring electrode 16. Consequently, if the user accidentally
touches the comb electrode l6C, he will also touch the conductive pattern 34C atthe same
time. As a result, static electricity from the user will flow through the conductive patterns
34C,34A, and 34B to the device side. This prevents damage to the measuring electrode 16
by static electricity. As a result, the measurement chip 15 is easier to handle and operate.
10
Also, with this device, when a microbe count is taken based on a minute impedance
change in the measuring electrode 16, since the measuring electrode 16, the connector 18,
and the connecting electrode 17 are surrounded by the conductive pattems 34A, 34B, and
15 34C,the conductive patterns 34A,348, and 34C become barriers that reduce disturbance
noise coming into the measurement chip 15.
Measuring Pure Water Temperature
In this embodiment, the structure is such that the conductive pattems 34A, 34B, and
34C are connected to the ground terminals 36,4, and 368 to counteract static electricity, but
20 these conductive patterns 34A,348, and 34C can also be used for measuring temperature.
If the ground terminal 36A shown in FIG. l1 is a voltage application terminal, and the
ground electrode 37A provided correspondingly to the measurement chip l5 is a voltage
24
application electrode, then DC current will flow from the conductive pattern 34A to the
conductive patterns 34B and 34C. As is commonly known, the resistance of a conduction
path changes with temperature, so the temperature of the pure water 8 shown in FIG. 9 can be
sensed by monitoring the voltage of the ground terminal 36,4.. Thus, this detected
5 temperature can be used to correct the impedance between the measuring electrodes 16,4. and
16B that is measured.
Specifrcally, the temperature of the pure water 8 is affected by how many microbes
,^ have been captured between the measwing electrodes 16,4' and 168, so more accurate
measurement can be performed by measuring the temperature of the pure water 8 and using it
l0 to correct the impedance.
Here again, the ground terminal 36B that is used to put the conductive patterns 34A,
34B, and 34C atthe ground potential is fomred longer than the ground terminal 36,{ serving
as the voltage application terminal, and the connection terminals 35A and 35B. Therefore,
during mounting of the measurement chip 15, the antistatic effect discussed above can be
l5 maintained by connecting the ground terminal 36B to the conductive patterns 34A, 34B, and
34C atthe very start.
That is, the conductive patterns 34A, 34B, and 34C in this case have both the function
of a conductive pattem and the function of a temperature measurement pattem.
In this embodiment, the length relation of the terminals is such that ground terminal
20 368 > connection terminal 35A > connection terminal 35B > ground terminal 36,{.
As discussed above, when the ground terminal 36A shown in FIG. 1l is the voltage
application terminal, a reference resistor is connected on the current upstream side thereol
25
l0
and DC crrrent flows from this reference resistor to the ground terminal 36A, the ground
electrode 37A, the conductive patterns 34A,348, and 34C, and the ground terminal 36B.
If the voltage between the reference resistor and the ground terminal 36,4. is measured,
it witl be possible to detect the temperature of the pure water 8 based on the change in the
resistance of the conductive patterns 34A,348, and 34C with the temperature of the pure
water 8.
The procedure for measuring the temperature of the pure water 8 with the
measurement chip 15 in this embodiment will now be described in detail.
As shown in FIG. 7, a conductor 41 (the conductive patterns 34A,348, and 34C) is
connected at its first end to the ground terminal 36A and at its second end to a resistance
measurement section 42.
The resistance measurement sectiort42 is configured such that DC resistance can be
leasured
in a state in which DC current is flowing to the conductive pattems 34A, 34B, and
34C.
More specifically, as shown in FIG. 12,the resistance measurement section 42 is
made up of a measuring resistor 43 and the power supply 23 that is connected to this
measuring resistor 43.
The terminal on the opposite side of the measuring resistor 43 from the side connected
to the power supply is connected to the second end of the conductive patterns 34A,348, and
20 34C.
With this configwation, the controller 25 reads the value of the voltage at the second
end of the conductive patterns 34A,348, and 34C, which allows the DC resistance of the
l5
26
conductive patterns 34A,348, and 34C to be detected. The temperature of analyte (the pure
water 8) can be measured on the basis of this DC resistance value.
With the measurement chip l5 in this embodiment, as discussed above, palladium is
used as the metal material of the electrode sputtered on a substrate such as PET. The reason
5 for using palladium is that it of[ers the following advantages.
' Its resistance value or the proportional change in resistance with respect to
temperature is relatively large, which makes measurement easier.
,. ' Palladium is less susceptible to changes over time, such as oxidation.
Since film formation and the like are easy to control in manufacture, error in the
10 resistance value can be reduced.
Evaluation of Measurement Chip l5
With the apparatus for measuring number of microbe in this embodiment, it is
possible to determine whether the measurement chip l5 has been mounted properly (and not
backward), or whether or not the measurement chip 15 is a genuine product.
15 Specifically, with the apparatus for measuring number of microbe of this embodiment,
just as in the detection of the temperature of the pure water 8 discussed above, the conduction
state (such as the DC resistance state) of the conductive patterns 34A,348, and 34C of the
measurement chip 15 inserted into the apparafus for measuring number of microbe is
monitored on the device side.
20 Whether or not the measurement chip l5 has been properly inserted (not backward)
can be detected here according to whether or not the resistance or other such detected value is
within the specified range.
27
n
For instance, if the measurement chip 15 has been inserted backward, the conductive
pattern will not be disposed on the rear side, so no current value (resistance value) will be
detected by the controller 25 onthe device side. Thus, whether or not the measurement chip
l5 has been inserted properly (not backward) can be easily determined on the basis of
whether or not a cwrent value has been detected at the controller 25.
If it is determined that the measurement chip 15 has been inserted backward, this is
dealt with, for example, by having the controller 25 display a message such as "chip not
inserted properly" on the display section 31 provided on the front of the device. Altematively,
a warning bluzzer may be sounded to alert the user to the fact that the measurement chip 15
has been inserted backward. l0
Also, whether or not the measurement chip l5 is a genuine product can be detected
with the apparatus for measuring number of microbe in this embodiment.
. Specifically, if a measurement chip that is not a genuine product is inserted, there is
the possibility that the current value detected with respect to a specific applied voltage will be
15 different from that of a genuine measurement chip 15, due to variance in quality, a difference
' in the composition of the metal material or the like that forms the electrodes, and so forth.
Thus, with this embodiment, whether or not the measurement chip 15 is a genuine
product is determined according to whether or not the current value read at the controller 25
falls within a specific range.
20 If the chip is found not to be a genuine product, the controller 25 puts an error display
on the display section 31 provided to the front of the device, and controls the device so that a
microbe count cannot be taken. Alternatively, a warningbuzzer is sounded to alert the user
28
to the fact that proper measurement may be impossible because the meastrement chip is not a
genuine product.
This encourages the user to use a measurement chip 15 that is a genuine product, so
that very accurate measurement can be reliably carried out.
5 INDUSTRIAL APPLICABILITY
With the chip for measuring number of microbe of the present invention, and the
apparatus for measuring number of microbe used for measurement with the same, an
n electrode insertion portion can be provided for inserting a measurement chip through an
opening into a container from above the container held by a container holder, and since this
10 container is one having a simple bottomed cylindrical shape with an opening in the upper
face, the container can be produced less expensively, and measurement costs can be lowered.
r Therefore, the present invention is expected to find wide application as a chip for measuring
1um-ber
of microbe for taking the count of microbes present in foods or in the mouth, and as
an apparatus for measuring number of microbe in which this chip is used.
I5 REFERENCE SIGNS LIST
n I mainbody case
2 front cover (electrode insertion portion)
3 container holder
4 container
20 5 holder
6 elution protrusion
7 elution groove
29
,^
n
l0
8 pure water (liquid)
9 microbe collection tool
l0 collection portion
ll switch
12 motor
13 operation lamp
14 measurement chip holder (electrode insertion portion)
15 measurement chip
l5A chip main body
16 measuring electrode
164,, 168 measuring electrode
16a 16b part
l6C comb electrode
17 connecting electrode
17 A, l7B connecting electrode
18 connector
18A, l8B connector
19 handle
20 measurement start switch
21 through-hole
2lA,2lB through-hole
22 manipulator
l5
20
30
lr
23 power supply
24 motor power supply
25 controller
26 motor power supply controller
5 27 electrode power supply
28 electrode power supply controller
29 measurement section
30 computer
3l display section
10 32 interface section
33 cover
33A,33B extension
34, 34A, 348, 34C conductive Pattem
35, 35A, 35B connection terminal
15 36A, 368 ground terminal
37 A,37F- ground electrode
38 measuring resistor
41 conductor (conductive pattern)
42 resistance measurement section
20 Ll shake amount
M microbes
3l
"1l
.rt
*
NE CLAIMS
1. A chip for measuring number of microbe, comprising:
a chip main body in the form of a long plate;
a measuring electrode that is provided on a first end side in the longitudinal direction
5 of the surface of the chip main body, and that is immersed in a measurement liquid;
a connecting electrode that is connected to the measuring electrode and is provided on
a second end side on the opposite side from the first end in the longitudinal direction of the
surface of the chip main body; n
a ground electrode that is provided on the second end side of the surface of the chip
l0 main body; and
a conductive pattem that is connected to the ground electrode and is provided to the
outer peripheral portion of the measuring electrode.
2. The chip for measuring number of microbe according to Claim l,
wherein the first end of the conductive pattem is connected to the ground electrode on
15 the second end side in the longitudinal direction of the surface of the chip main body, and
,,F\ the second end of the conductive pattern is provided around the outer periphery of the
measuring electrode on the first end side in the longitudinal direction of the surface of the
chip main body, and extends to the second end side in the longitudinal direction of the
surface of the chip main body.
20 3. The chip for measuring number of microbe according to Claim 2,
wherein the second end of the conductive pattem is provided around the outer
periphery of the measuring electrode on the first end side in the longitudinal direction of the
32
surface of the chip main body, extends to the second end side in the longitudinal direction of
the surface of the chip main body, and is connected to the ground electrode provided on the
second end side in the longitudinal direction of the surface of the chip main body.
4. The chip for measuring number of microbe according to Claim 2,
5 wherein the second end of the conductive pattem is provided around the outer
periphery of the measuring electrode on the fnst end side in the longitudinal direction of the
surface of the chip main body, extends to the second end side in the longitudinal direction of
the surface of the chip main body, and is connected to a voltage application electrode n
provided on the second end side in the longitudinal direction of the surface of the chip main
10 body.
5. The chip for measuring number of microbe according to Claim 1,
wherein the measuring electrode has mutually opposing first and second measuring
electrodes on the first end side in the longitudinal direction of the surface of the chip main
body, and
15 the first and second measuring electrodes have mutually opposing comb electrodes
n formed a specific distance apart.
6. The chip for measuring number of microbe according to Claim 1,
wherein the a connection pattern that connects the connecting electrode and the
measuring electrode is covered by a covering body between the first end and second end in
20 the longitudinal direction of the surface of the chip main body.
7. An apparatus for measuring number of microbe in which the chip for measuring
number of microbe according to Claim I is used, comprising:
33
a container holder that holds a bottomed cylindrical container having an opening in its
upper face, with the opening facing up;
a rotary driver that rotates a liquid stored inside the container held in the container
holder, around the central axis of the container running in a substantially vertical direction;
an electrode insertion portion for inserting the chip for measuring number of microbe,
through the opening in the container held in the container holder, at a position inside the
container that is closer to the inner wall side than the central axis, and a position that is a
specific distance away from the irurer wall surface; and
a measurement section that measures microbes at the measurement electrode of the
chip for measuring number of microbe inserted into the container by the electrode insertion
portion.
10
An apparatus for measuring number of microbe in which the chip for measuring
number of microbe according to Claim 3 is used, comprising:
a container holder that holds a bottomed cylindrical container having an opening in its
l5 upper face, with the opening facing up;
rrt.
a rotary driver that rotates a liquid stored inside the container held in the container
holder, around the central axis of the container running in a substantially vertical direction;
an electrode insertion portion for inserting the chip for measuring number of microbe,
through the opening in the container held in the container holder, at a position inside the
20 container that is closer to the inner wall side than the central axis, and a position that is a
specific distance away from the inner wall surface; and
34
n
a measurement section that measures microbes at the measurement electrode of the
chip for measuring number of microbe inserted into the container by the electrode insertion
portion,
wherein the electrode insertion portion has:
5 a connection terminal that is connected to the connecting electrode of the chip for
measuring number of microbe; and
a ground terminal that is connected to the ground electrode of the chip for measuring
number of microbe, and
the ground terminal and the ground electrode are connected before the connection
l0 terminal and the connecting electrode are connected.
9. The apparatus for measuring number of microbe according to Clairn 8,
wherein the ground tenninal of the electrode insertion portion is longer than the
connection terminal.
10. An apparatus for measuring number of microbe in which the chip for measuring
15 number of microbe according to Claim 4 is used, comprising:
A.
a container holder that holds a bottomed cylindrical container having an opening in its
upper face, with the opening facing up;
a rotary driver that rotates a liquid stored inside the container held in the container
holder, around the central axis of the container running in a substantially vertical direction;
20 an electrode insertion portion for inserting the chip for measuring number of microbe,
through the opening in the container held in the container holder, at a position inside the
35
container that is closer to the imer wall side than the central axis, and a position that is a
specific distance away from the inner wall surface; and
a measurement section that measures microbes at the measurement electrode of the
chip for measuring number of microbe inserted into the container by the electrode insertion
5 portion,
wherein the electrode insertion portion has:
a connection terminal that is connected to the connecting electrode of the chip for
measuring number of microbe; n
a ground terminal that is connected to the ground electrode of the chip for measuring
l0 number of microbe; and
a voltage application terminal that is connected to the voltage application electrode of
the chip for measuring number of microbe, and
the ground terminal and the ground electrode are connected before the connection
terminal and the connecting electrode are connected.
l5 11. The apparatus for measuring number of microbe according to Claim 10,
A wherein the connection terminal and the connecting electrode are connected before
the voltage application terminal and the voltage application electrode are connected.
12- The apparatus for measuring number of microbe according to Claim I l,
wherein the ground terminal of the electrode insertion portion is longer than the
20 connection terminal, and the connection terminal is longer than the voltage application
terminal.
36
13. A chip for measuring number of microbe, comprising:
a chip main body in the form of a long plate;
a measuring electrode that is provided on the lower end side of the surface of the chip
main body, is immersed in a measurement liquid, and has mutually opposing first and second
measuring electrodes on the lower end side of the surface of the chip main body;
a connecting electrode that is provided on the upper end side of the surface of the chip
main body, is connected to a mezmurement device, and has first and second connecting
electrodes;
a connector that connects the measuring electrode and the connecting electrode at the
,.t
surface of the chip main body, and has a first connector where the first measuring electrode
and fte first oonnecting elechode are connected between the upper and lower ends of the
surface of the chip main body, and a second connector where the second measuring electrode
and the secontl connecting electrode are connected between the upper and lower ends of the
surface of the chip main body; and
wherein the widths of the first and second connectors in the short-side direction are
substantially the same, and are substantially one half the width of the chip main body in the
short-side direction.
15. The chip for measuring number of microbe according to Claim 13 or 14,
wherein the fust and second measuring electrodes form comb electrodes a specific
distance apart, and
10
a cover that is provided so as to cover the surface ofthe first and second connectors
15 between the upper and lower ends of the surface of the chip main body.
' 14. The chip for measuring number of microbe according to Claim 13,
20
37
the comb electrodes have a rectangular shape that is longer in the longitudinal
direction of the chip main body, and are disposed in the center of the chip main body in the
short-side direction on the lower end side of the sur ce of the chip main body.
16. The chip for measuring number of microbe according to Claim 15,
5 wherein the cover is in the form of a long plate, and a center of the lower end of the
cover is disposed more on the upper end side of the chip main body than the measuring
electrode of the chip main body.
17. The chip for measuring number of microbe according to Claim 16,
wherein both sides of the cover on the lower end side extend to the lower end of the
l0 chip main body, and
the extension portions of both sides do not cover the comb electrodes of the
measuring electrodes immersed in the measurement liquid.
The chip for measuring number of microbe according to any of Claims 13 to 17,
wherein a first through-hole for separating from a measurement device to which the
l5 chip main body is mounted is provided in the middle of the chip main body, and
^\ ' the upper end of the cover is disposed more to the upper end side of the chip main
body than the first through-hole of the chip main body.
19. An apparatus for measuring number of rnicrobe in which the chip for measuring
number of microbe according to any of Claims 13 to 18 is used, comprising:
20 a container holder that holds a bottomed cylindrical container having an opening in its
upper face, with the opening facing up;
38
.a rotary driver that rotates a liquid stored inside the container held in the container
holder, around the central axis of the container rururing in a substantially vertical direction;
an electrode insertion portion for inserting the chip for measuring number of microbe,
through the opening in the container held in the container holder, at a position inside the
5 container that is closer to the inner wall side than the central axis, and a position that is a
specific distance away from the irurer wall surface; and
a measurement section that measures microbes at the measurement electrode of the
chio for measuring number of microbe inserted into the container by the electrode insertion n
portion.
l0 20. The apparatus for measuring number of microbe according to Claim 19,
wherein the rotary driver rotates the liquid inside the container by rotating the
container held in the container holder around the center axis.