U.S. patent application number 13/252433 was filed with the patent office on 2012-01-26 for blood sensor, blood testing apparatus, and method for controlling blood testing apparatus.
Invention is credited to Shusei AIBARA, Masaki FUJIWARA, Noriyoshi TERASHIMA.
Application Number | 20120022352 13/252433 |
Document ID | / |
Family ID | 38088471 |
Filed Date | 2012-01-26 |
United States Patent
Application |
20120022352 |
Kind Code |
A1 |
FUJIWARA; Masaki ; et
al. |
January 26, 2012 |
BLOOD SENSOR, BLOOD TESTING APPARATUS, AND METHOD FOR CONTROLLING
BLOOD TESTING APPARATUS
Abstract
A blood sensor includes a base (12), a detection part (16)
disposed on the base (12), a blood collection needle (13) disposed
at a front end (12a) of the base (12), a negative pressure
generation part (17) for applying negative pressure to a portion of
the blood collection needle (13), and a supply path (15) for
supplying blood collected by the blood collection needle (13) to a
detection part (16).
Inventors: |
FUJIWARA; Masaki; (Ehime,
JP) ; TERASHIMA; Noriyoshi; (Ehime, JP) ;
AIBARA; Shusei; (Ehime, JP) |
Family ID: |
38088471 |
Appl. No.: |
13/252433 |
Filed: |
October 4, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11545468 |
Oct 11, 2006 |
8057404 |
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13252433 |
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Current U.S.
Class: |
600/347 ;
600/345 |
Current CPC
Class: |
A61B 5/150511 20130101;
A61B 5/150389 20130101; A61B 5/150083 20130101; A61B 5/150099
20130101; A61B 5/150618 20130101; A61B 5/15113 20130101; A61B
5/1519 20130101; A61B 5/1486 20130101; A61B 5/150541 20130101; A61B
5/157 20130101; A61B 5/150717 20130101; A61B 5/150358 20130101;
A61B 5/150022 20130101; A61B 5/15117 20130101; A61B 5/150282
20130101; A61B 5/150229 20130101; A61B 5/14535 20130101; A61B
5/150977 20130101 |
Class at
Publication: |
600/347 ;
600/345 |
International
Class: |
A61B 5/157 20060101
A61B005/157 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 12, 2005 |
JP |
2005-297506 |
Claims
1. A blood sensor comprising: a base; a needle for blood collection
which disposed at a front end of the base, and a detection part for
detecting a component of blood collected by the blood collection
needle with use of a reagent, and a blood supply path for supplying
the blood collected by the blood collection needle to the detection
part, the detection part and the blood supply path being provided
in the base, wherein the detection part includes a working
electrode, a counter electrode and a hematocrit electrode for
detecting a hematocrit value.
2. The blood sensor according to claim 1, wherein the detection
part further includes a sensing electrode for sensing a flow of
blood.
3. The blood sensor according to claim 1, wherein the base is
formed by laminating and adhering a substrate, a spacer and a
cover.
4. The blood sensor according to claim 3, wherein the substrate,
the spacer and the cover comprise polyethylene terephthalate.
5. The blood sensor according to claim 3, wherein contact
electrodes connected to the respective electrodes of the detection
part are formed on an upper surface of the substrate, and the
contact electrodes include a conductive layer which is formed on
the upper surface of the substrate by conducting sputtering or
vapor deposition of gold, platinum or palladium and then by
conducting laser processing thereto.
6. The blood sensor according to claim 1, wherein the detection
part is used for measuring an amount of glucose.
7. The blood sensor according to claim 1, wherein the reagent
includes glucose dehydrogenase (GDH).
8. The blood sensor according to claim 1, wherein the reagent
includes potassium ferricyanide.
9. The blood sensor according to claim 1, wherein at least one
surface of the detection part is formed of a transparent
material.
10. The blood sensor according to claim 1, further comprising a
blood collection needle cover which covers the blood collection
needle and is formed integrally with the base.
11. The blood sensor according to claim 1, wherein the blood
collection needle is formed of metal or plastic.
12. The blood sensor according to claim 11, wherein a plurality of
the blood collection needles are provided in parallel with each
other at the front end of the base.
13. The blood sensor according to claim 11, wherein the blood
collection needle has a triangular cross section.
14. The blood sensor according to claim 11, wherein the blood
collection needle has a circular cross section.
15. The blood sensor according to claim 11, wherein the blood
collection needle has a rectangular cross section.
16. The blood sensor according to claim 11, wherein the blood
collection needle has a polygonal section.
17. The blood sensor according to claim 11, wherein a through-hole
is formed in the blood collection needle so as to penetrate between
both ends of the blood collection needle.
18. A blood testing apparatus used for measuring an amount of
glucose, the apparatus comprising: a cylindrical casing; an
insertion port into which the blood sensor according to claim 1 is
inserted, and a contact terminal to be connected to a contact
electrode provided on the blood sensor.
Description
[0001] This application is a continuation of application Ser. No.
11/545,468, filed Oct. 11, 2006.
FIELD OF THE INVENTION
[0002] The present invention relates to a blood sensor, a blood
testing apparatus, and a method for controlling the blood testing
apparatus.
BACKGROUND OF THE INVENTION
[0003] Hereinafter, a conventional blood sensor and a blood testing
apparatus using the blood sensor will be described with respect to
a sensor and a testing apparatus used for diabetes testing.
[0004] A diabetic patient measures his/her blood glucose level
periodically, and injects insulin on the basis of the blood glucose
level to keep a normal blood glucose level. Conventionally, in
order to measure blood glucose level, a small amount of blood is
collected from a finger tip or the like of a patient using a
puncture unit, and then the blood glucose level of the collected
blood is measured using a measurement unit.
[0005] More specifically, as shown in FIG. 14, initially a puncture
needle port 2 of a puncture unit 1 is applied to a finger tip or
the like of a patient. Thereafter, a button 3 is pressed. Then, a
needle protrudes from the puncture needle port 2 at high speed and
goes back instantly, whereby the needle makes a minute wound on the
finger tip or the like. The patient squeezes blood from this wound
to collect the same.
[0006] Next, using a testing unit 4 for measuring blood glucose
level shown in FIG. 15, the patient applies the collected blood
onto a blood attachment part 5a of a sensor 5 that is inserted in
the testing unit 4. Thereby, the testing unit 4 calculates blood
glucose level of the attached blood, and displays the result of
calculation on a display unit 6.
[0007] As prior art document information relating to the invention
of this application, for example, Japanese Published Patent
Application No. 2002-219114, and a brochure of International
Publication No. 2005/054840 are known.
[0008] In the conventional testing of blood glucose level, however,
it is necessary to use two units, i.e., the puncture unit 1 and the
testing unit 4. That is, it is necessary for the patient to make a
wound on his/her skin at a finger tip or the like, squeeze blood
from this wound, and apply the blood onto the blood attachment part
5a of the sensor 5. This operation is very complicated.
SUMMARY OF THE INVENTION
[0009] The present invention is made to solve the above-described
problems and has for its objective to provide a blood sensor and a
blood testing apparatus with which blood testing can be easily
carried out, and a method for controlling the blood testing
apparatus.
[0010] Other objects and advantages of the invention will become
apparent from the detailed description that follows. The detailed
description and specific embodiments described are provided only
for purposes of illustration since various additions and
modifications within the scope of the invention will be apparent to
those of ordinary skill in the art from the detailed
description.
[0011] According to a first aspect of the present invention, a
blood sensor comprises a base, a hollow needle for blood collection
which is disposed at a front end of the base; a detection part for
detecting a component of blood collected by the blood collection
needle and a blood supply path for supplying the blood collected by
the blood collection needle to the detection part, which are
provided in the base, and a negative pressure generation part for
applying negative pressure to the hollow part of the blood
collection needle through a negative pressure supply path, which is
provided in approximately the center of the base.
[0012] Therefore, it is possible to provide a blood sensor which
can supply the blood collected by the blood collection needle to
the detection part without intervening manual work, and detect the
blood.
[0013] According to a second aspect of the present invention, in
the blood sensor according to the first aspect, the blood supply
path shares a portion with the negative pressure supply path that
forms the negative pressure generation part, and the detection unit
is provided at an end of the blood supply path that shares a
portion with the negative pressure supply path.
[0014] Therefore, it is possible to fabricate a blood sensor in a
simple construction.
[0015] According to a third aspect of the present invention, in the
blood sensor according to the first aspect, detection electrodes
are disposed on the detection part, and contact electrodes
connected to the detection electrodes are disposed on an end
surface of the base.
[0016] According to a fourth aspect of the present invention, in
the blood sensor according to the first aspect, the blood
collection needle comprises plastic.
[0017] Therefore, the blood collection needle can be easily
fabricated, and needle-stick accidents can be reduced.
[0018] According to a fifth aspect of the present invention, in the
blood sensor according to the first aspect, the hollow blood
collection needle has a circular cross section.
[0019] Therefore, the blood collection needle can easily be set on
the blood sensor, and thereby fabrication is facilitated.
[0020] According to a sixth aspect of the present invention, in the
blood sensor according to the first aspect, the hollow blood
collection needle has a triangular cross section.
[0021] According to a seventh aspect of the present invention, in
the blood sensor according to the first aspect, the hollow blood
collection needle has a polygonal cross section.
[0022] Therefore, the thickness of the tip of the blood collection
needle is increased, whereby the strength of the needle tip can be
increased.
[0023] According to an eighth aspect of the present invention, in
the blood sensor according to the first aspect, a blood collection
needle cover that covers the blood collection needle is formed
integrally with the base.
[0024] Therefore, it is possible to provide a safe and preferable
blood sensor.
[0025] According to a ninth aspect of the present invention, in the
blood sensor according to the first aspect, a plurality of the
blood collection needles are provided in parallel with each other
at the front end of the base.
[0026] Therefore, it is possible to provide a highly reliable and
safe blood sensor.
[0027] According to a tenth aspect of the present invention, in the
blood sensor according to the first aspect, at least one surface of
the detection part comprises a transparent material.
[0028] Therefore, the scale of the blood sensor can be reduced.
[0029] According to an eleventh aspect of the present invention, a
blood testing apparatus comprises a cylindrical casing, a slider
that is forward or backward movably provided in the cylindrical
casing, a blood that is attached at a front end of the slider; a
first negative pressure generator for supplying negative pressure
to a negative pressure generation part provided in the blood
sensor, and a blood collection button for instructing the slider to
move forward.
[0030] Therefore, it is possible to provide a blood sensor which
can supply the blood collected by the blood collection needle to
the detection part without intervening manual work, and detect the
blood.
[0031] According to a twelfth aspect of the present invention, in
the blood testing apparatus according to the eleventh aspect, a
cylindrical cap is provided at a front end of the casing.
[0032] Therefore, the blood collection needle is not exposed,
whereby safety is secured, and the patient is not scared by the
needle. Furthermore, even when the blood testing apparatus is
dropped to the floor, accidents such as breakage of the blood
collection needle are avoided.
[0033] According to a thirteenth aspect of the present invention,
the blood testing apparatus according to the eleventh aspect
further includes a second negative pressure generator for supplying
negative pressure, which is provided in the casing.
[0034] Therefore, a measurement site of a patient can be easily
punctured with the blood collection needle.
[0035] According to a fourteenth aspect of the present invention,
in the blood testing apparatus according to the eleventh aspect,
forward movement of the slider is given momentum by a coil
spring.
[0036] Therefore, puncture to a measurement site of a patient can
be carried out more easily.
[0037] According to a fifteenth aspect of the present invention,
the blood testing apparatus according to the eleventh aspect
further includes a vibration generator for vibrating the blood
collection needle.
[0038] Therefore, blood collection can be carried out more
easily.
[0039] According to a sixteenth aspect of the present invention, a
blood testing apparatus comprises a cylindrical casing, a slider
that is forward or backward movably provided in the cylindrical
casing, a blood sensor that is attached at a front end of the
slider, a first negative pressure generator for supplying negative
pressure to a negative pressure generation part provided in the
blood sensor, a blood collection button for instructing the slider
to move forward, contact terminals to which the contact electrodes
provided in the blood sensor are connected, the contact terminals
being provided on the slider, and a measurement unit for measuring
a component of blood that is collected and detected by the blood
sensor, the measurement unit being connected to the contact
terminals.
[0040] Therefore, the blood collected by the blood collection
needle can be supplied to the detection part without intervening
manual work to measure components of the blood.
[0041] According to a seventeenth aspect of the present invention,
in the blood testing apparatus according to the sixteenth aspect,
the measurement unit comprises an I/V converter connected to the
contact terminals, an A/D converter to which an output of the I/V
converter is connected, an operation unit having an input to which
an output of the A/D converter is connected, and the other input to
which an output of a control unit is connected, and a display unit
to which an output of the operation unit is connected.
[0042] Therefore, the components of the collected blood can be
measured and displayed.
[0043] According to an eighteenth aspect of the present invention,
the blood testing apparatus according to the seventeenth aspect
further includes a transmission unit for transmitting the result of
operation obtained by the operation unit, the transmission unit
being connected to the control unit.
[0044] Therefore, the result of operation obtained by the blood
testing apparatus can be transmitted to another apparatus to set a
value based on the result of operation of the apparatus, and
thereby a setting error on the apparatus can be avoided.
[0045] According to a nineteenth aspect of the present invention, a
method for controlling a blood testing apparatus comprises an
attachment step of attaching the blood sensor to the blood testing
apparatus, a puncture preparation step of applying the blood
testing apparatus to a measurement site, after the attachment step,
a puncture operation step of puncturing the measurement site with
the blood collection needle, after the puncture preparation step, a
blood collection step of applying negative pressure to the hollow
part of the blood collection needle by the first negative pressure
generator to collect blood from the measurement site, after the
puncture operation step, and a measurement step of detecting and
measuring a component of the collected blood, after the blood
collection step.
[0046] Therefore, the blood collected by the blood collection
needle can be supplied to the detection part without intervening
manual work to measure components of the blood.
[0047] According to a twentieth aspect of the present invention, in
the method for controlling a blood testing apparatus according to
the nineteenth aspect the blood collection needle is vibrated by
the vibration generator in the blood collection step.
[0048] Therefore, blood collection can be facilitated. According to
a twenty-first aspect of the present invention, in the method for
controlling a blood testing apparatus according to the nineteenth
aspect, in the attachment step, a cap is put on the front end of
the casing of the blood testing apparatus after a blood collection
needle cover that covers the blood collection needle of the blood
sensor is removed.
[0049] Therefore, the blood collection needle is prevented from
scaring the patient, and accidents such as breakage of the needle
can be avoided.
[0050] According to a twenty-second aspect of the present
invention, in the method for controlling a blood testing apparatus
according to the twenty-first aspect, in the puncture preparation
step, the cap is applied to a measurement site, and negative
pressure is added into the casing the blood testing apparatus
including the cap by the second negative pressure generator.
[0051] Therefore, the measurement site of the patient can be easily
punctured with the blood collection needle.
[0052] According to twenty-third aspect of the present invention,
in the method for controlling a blood testing apparatus according
to the nineteenth aspect, after the measurement step, the measured
data are transmitted to an injection unit for a curative drug.
[0053] Therefore, a dose of insulin to be administered to the
patient can be automatically set on the injection unit, whereby the
patient is saved from the trouble of setting the dose of insulin on
the injection unit. Further, the dose of insulin can be set on the
injection unit without intervening manual work, thereby avoiding
setting error.
EFFECTS OF THE INVENTION
[0054] The blood sensor according to the present invention is
provided with the base; the detection part disposed in the base,
the hollow blood collection needle provided at the front end of the
base, the negative pressure generation part for applying negative
pressure to the blood collection needle, and the supply path for
supplying the blood collected by the blood collection needle to the
detection part. Since the blood sensor itself has the blood
collection needle, the skin of the patient can be punctured with
the blood collection needle, and simultaneously, blood can be
collected with the needle.
[0055] Moreover, the collected blood is guided as it is to the
detection part without intervening manual work to be tested as it
is.
[0056] Accordingly, in the blood testing apparatus provided with
the above-mentioned blood sensor and the method for controlling the
blood testing apparatus, there is no burden of using a puncture
apparatus and a measurement apparatus separately, and blood
collection and testing can be easily carried out.
BRIEF DESCRIPTION OF THE DRAWINGS
[0057] FIG. 1 is a plan view of a blood sensor according to a first
embodiment of the present invention.
[0058] FIG. 2 is a cross-sectional view of the blood sensor
according to the first embodiment.
[0059] FIGS. 3(a)-3(d) are exploded plan views of the blood sensor
according to the first embodiment, and FIG. 3(a) is a plan view of
a cover of the blood sensor, FIG. 3(b) is a plan view of a spacer
of the blood sensor, FIG. 3(c) is a plan view of a substrate of the
blood sensor, and FIG. 3(d) is a plan view of an assembled blood
sensor.
[0060] FIGS. 4(a)-4(d) are front views and side views of a blood
collection needle according to a second embodiment, of the blood
sensor according to the first embodiment, and FIG. 4(a) is front
and side views of a needle having a triangle side surface, FIG.
4(b) is front and side views of a needle having a circular side
surface, FIG. 4(c) is front and side views of a needle having a
rectangle side surface, and FIG. 4(d) is front and side views of a
needle having a hexagonal side surface.
[0061] FIGS. 5(a)-5(d) are plan views before disconnection of blood
collection needle covers according to a third embodiment of the
present invention, and FIG. 5(a) is a plan view before
disconnection of the needle cover for a cover, FIG. 5(b) is a plan
view before disconnection of the needle cover for a spacer, FIG.
5(c) is a plan view before disconnection of the needle cover for a
substrate, and FIG. 5(d) is a plan view of an assembled blood
sensor.
[0062] FIG. 6 is a fabrication process chart of a blood sensor
according to a fourth embodiment of the present invention.
[0063] FIG. 7 is a plan view of a blood sensor according to a fifth
embodiment of the present invention.
[0064] FIG. 8 is a plan view of a blood sensor according to a sixth
embodiment of the present invention.
[0065] FIG. 9 is a transparent plan view of a blood sensor inserted
into a blood testing apparatus according to a seventh embodiment of
the present invention.
[0066] FIGS. 10(a)-10(e) are cross-sectional views of a blood
testing apparatus according to the seventh embodiment, and FIG.
10(a) is a cross-sectional view of the apparatus showing attachment
of a blood sensor, FIG. 10(b) and FIG. 10(c) are cross-sectional
views of the apparatus during puncture preparation, FIG. 10(d) is a
cross-sectional view of the apparatus during puncture operation,
and FIG. 10(e) is a cross-sectional view of the apparatus during
blood collecting operation.
[0067] FIG. 11 is a block diagram of the blood testing apparatus
according to the seventh embodiment.
[0068] FIG. 12 is a flowchart for explaining a blood testing
process according to the seventh embodiment.
[0069] FIG. 13 is a block diagram of a blood testing apparatus
according to an eighth embodiment.
[0070] FIG. 14 is a perspective view of a conventional puncture
apparatus.
[0071] FIG. 15 is a plan view of a conventional measurement
apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0072] Hereinafter, embodiments of the present invention will he
described with reference to the drawings.
Embodiment 1
[0073] FIG. 1 is a plan view illustrating a blood sensor 11
according to a first embodiment of the present invention.
[0074] With reference to FIG. 1, a base 12 of the blood sensor 11
has a bell shape, and a hollow needle for blood collection is
attached to a front end 12a of the base 12. A blood supply path 16a
for supplying the blood component collected by the blood collection
needle 13 to a detection part 16 is led from a attachment part 14
to which the blood collection needle 13 is attached, and this blood
supply path 16a shares a portion with a negative pressure supply
path 17c that forms a negative pressure generation part 17 for
applying negative pressure to the follow portion of the blood
collection needle 13. In order to simplify the following
description, it is assumed that the negative pressure supply path
17c and the blood supply path 16a constitute a supply path 15.
[0075] The detection part 16 includes detection electrodes 18, 19,
20, and 21 comprising a conductive material. The detection
electrodes 18, 19, 20, and 21 are led to the other end 12b of the
base 12, thereby forming contact electrodes 18a, 19a, 20a, and 21a,
respectively.
[0076] FIG. 2 is a cross-sectional view of the blood sensor 11
according to the first embodiment. With reference to FIG. 2, the
base 12 comprises a substrate 22, a spacer 23 that is put on the
upper surface of the substrate 22, and a cover 24 that is put on
the upper surface of the spacer 23. The blood collection needle 13
is attached to the front end 12a of the base 12, and the supply
path 15 extends toward the other end 12b of the base 12 from the
attachment part 14 to which the blood collection needle 13 is
attached. The detection part 16 is disposed in the middle of the
supply path 15, and a reagent 25 is disposed on the detection part
16.
[0077] Further, at an end of the supply path 15, the negative
pressure generation part 17 is disposed toward the surface side of
the cover 24, and negative pressure is supplied from the negative
pressure generation part 17 to the blood collection needle 13.
[0078] FIGS. 3(a)-3(d) are exploded plan views of the blood sensor
11 according to the first embodiment. FIG. 3(c) is a plan view of
the substrate 22, and its width 22a and length 22b are 12 mm and 5
mm, respectively.
[0079] Further, a front end 22c of the substrate 22 is semicircular
in shape, and a radius of the semicircle is 2.5 mm. The substrate
22 comprises polyethylene terephthalate (PET) having a thickness of
0.5 mm (ranging from 0.1 to 0.6 mm).
[0080] A conductive layer is formed on the upper surface of the
substrate 22 by depositing gold, platinum, or palladium by
sputtering or vapor deposition, and the conductive layer is
subjected to laser processing to integrally fabricate the detection
electrodes 18.about.21 and the contact electrodes 18a.about.21a
which are connected to the detection electrodes 18.about.21,
respectively.
[0081] FIG. 3(b) is a plan view of the spacer 23 included in the
blood sensor 11 according to the first embodiment, and its width
23a and length 23b are 9 mm and 5 mm, respectively. A front end 23c
of the spacer 23 is semicircular in shape, and a radius of the
semicircle is 2.5 mm. The spacer 23 comprises polyethylene
terephthalate (PET) having a thickness of 0.1 mm (ranging from 0.05
to 0.25 mm).
[0082] A slit 15a is formed from the front end 23c so as to be
connected to a hole 17a that forms the negative pressure generation
part 17, and a width 15b and a length 15c of the slit 15a are 0.5
mm and 4.35 mm, respectively. Accordingly, this slit 15a, the
substrate 22, and the cover 24 form the supply path 15 having a
thickness of 0.1 mm, a width of 0.5 mm, and a length of 4.35 mm.
Therefore, when a fluid such as blood is applied to the supply path
15, capillary phenomenon occurs.
[0083] Further, an attachment concave part 14a that forms the
attachment part 14 is disposed between the front end 23c and a
beginning end of the slit 15a, while an attachment convex part 14b
that fits the attachment concave part 14a is formed in the blood
collection needle 13. Accordingly, the blood collection needle 13
is firmly fixed to the attachment part 14 of the spacer 23.
[0084] FIG. 3(a) is a plan view of the cover 24 included in the
blood sensor 11 according to the first embodiment. The cover 24 has
a width 24a of 9 mm, and a length 24b of 5 mm. A front end 24c of
the cover 24 is semicircular in shape, and a radius of the
semicircle is 2.5 mm.
[0085] Further, a hole 17b having a diameter of lmm is formed in
the cover 24, and this hole 17b is communicated with the hole 17a
formed in the spacer 23, thereby forming the negative pressure
generation part 17.
[0086] The cover 24 comprises polyethylene terephthalate (PET)
having a thickness of 0.1 mm (ranging from 0.05 mm.about.0.2 mm). A
portion of the cover 24 corresponding to a ceiling of the supply
path 15 is subjected to hydrophilic processing to make blood flow
into the supply path 15 smoothly by capillary phenomenon.
[0087] FIG. 3(d) is a plan view of the base 12 of the blood sensor,
and a width 12c and a length 12d of the base 12 are 12 mm and 5 mm,
respectively. A front end 12a of the base 12 is semicircular in
shape, and a radius of the semicircle is 2.5 mm.
[0088] The contact electrodes 18a-21a are exposed in a region of
the base 12 corresponding to a length 12e from the other end 12b of
the base 12.
[0089] Further, the spacer 23 and the cover 24 are disposed back by
the length 12e from the other end 12b.
[0090] A spacing 12f between the detection part 16 and the negative
pressure generation part 17 is about 1 mm. This spacing prevents
blood from leaking out of the negative pressure generation part 17
when the negative pressure is stopped.
[0091] The base 12 is obtained by laminating and adhering the
substrate 22, the spacer 23, and the cover 24. Since polyethylene
terephthalate (PET) is used as a material of these components, it
is easy to manage the base 12.
[0092] Further, a reagent 25 is disposed on the detection part 16.
The reagent 25 is produced by preparing a reagent solution by
adding such as PQQ-GDH and potassium ferricyanide into CMC aqueous
solution, dropping the reagent solution onto the detection
electrodes 18 and 20 of the substrate 22, and drying the reagent
solution.
[0093] According to the first embodiment of the present invention,
since the blood sensor 11 itself has the blood collection needle
13, it is possible to simultaneously perform puncture of needle
into the skin as well as blood collection, using the blood
collection needle 13.
[0094] Moreover, since the collected blood is guided to the
detection part 16 without intervening manual work, the blood can be
tested as it is.
[0095] Accordingly, blood testing can be easily carried out without
the troubles in the conventional apparatus.
[0096] Further, since the blood collection needle 13 has the
negative pressure generation part 17 for applying negative pressure
to the needle, blood collection can be carried out speedily and
reliably.
Embodiment 2
[0097] FIGS. 4(a)-4(d) are front views and side views of various
shapes of blood collection needles 13 according to a second
embodiment of the present invention. The same components are given
the same reference numerals to simplify the description.
[0098] As a material of the blood collection needle 13 shown in
FIGS. 4(a)-4(d), metal (SUS304) or plastic (PEEK: polyether ether
ketone) may be used. When metal is adopted, a strong and
easy-to-puncture blood collection needle 13 can be produced.
[0099] When plastic is used, the blood collection needle 13 can be
easily fabricated by extrusion molding, and further, the needle 13
has elasticity that reduces needle-stick accidents to the
patient.
[0100] In FIG. 4(a), a blood collection needle 13a has a triangular
side surface, and its length 26a and height 27a are 1 mm and 0.155
mm, respectively. An angle 28a at the front end is 15.degree.. A
diameter 29a of the side surface is 0.2 mm, and a through-hole
having a diameter 30a of 0.05 mm is formed in the center of the
diameter 29a, and the collected blood flows into the
through-hole.
[0101] As shown in FIG. 4(a), since the blood collection needle 13a
of the blood sensor 11 according to the second embodiment has the
triangular side surface, the thickness of the front end portion 31a
increases, whereby the strength of the needle tip of the blood
collection needle 13a can be increased.
[0102] Further, since the apex of the triangular shape corresponds
to the front end portion 31a, the needle tip becomes sharper, and
thereby the needle can easily run into the skin. Further,
incorporation of the blood collection needle 13a into the spacer 23
constituting the sensor 11 is also facilitated.
[0103] With reference to FIG. 4(b), a blood collection needle 13b
has a circular side surface, and its length 26b and height 27b are
1 mm and 0.2 mm, respectively. An angle 28b of a front end portion
31b is 15.degree.. A diameter 29b of the side surface is 0.2 mm. A
through-hole having a diameter 30b of 0.05 mm is formed in the
center of the diameter 29b, and the collected blood flows into the
through-hole.
[0104] As shown in FIG. 4(b), since the blood collection needle 13b
of the blood sensor 11 according to the second embodiment has the
circular side surface, it is possible to incorporate the blood
collection needle 13b into the spacer 23 constituting the blood
sensor 11, without the necessity of paying attention to the
rotation direction, and further, fabrication of the needle 13b is
facilitated.
[0105] With reference to FIG. 4(c), a blood collection needle 13c
has a rectangle side surface, and its length 26c and height 27c are
1 mm and 0.2 mm, respectively. An angle 28c of a front end portion
31c is 15.degree.. A diameter 29c of the side surface is 0.2 mm. A
through-hole having a diameter 30c of 0.05 mm is formed in the
center of the diameter 29c, and the collected blood flows into the
through-hole.
[0106] As shown in FIG. 4(c), since the blood collection needle 13c
of the blood sensor 11 according to the second embodiment has the
rectangular side surface, the thickness of the front end portion
31c increases, whereby the strength of the tip of the blood
collection needle 13c can be increased.
[0107] Further, since the apex of the rectangular shape corresponds
to the front end portion 31c, the needle tip becomes sharper, and
thereby the needle can easily run into the skin. Further,
incorporation of the blood collection needle 13c into the spacer 23
constituting the sensor 11 is also facilitated.
[0108] With reference to FIG. 4(d), a blood collection needle 13d
has a hexagonal side surface, and its length 26d and height 27d are
1 mm and 0.2 mm, respectively. An angle 28d of a front end portion
31d is 15.degree.. A diameter 29d of the side surface is 0.2 mm. A
through-hole having a diameter 30d of 0.05 mm is formed in the
center of the diameter 29d, and the collected blood flows into the
through-hole.
[0109] As shown in FIG. 4(d), since the blood collection needle 13d
of the blood sensor 11 according to the second embodiment has the
hexagonal side surface, incorporation of the blood collection
needle 13d into the spacer 23 constituting the sensor 11 is
facilitated.
[0110] According to the blood sensor 11 of the second embodiment,
metal (SUS304) or plastic (PEEK: polyether ether ketone) is used as
a material of the blood collection needle 13. Therefore, when metal
is used, a strong and easy-to-puncture blood collection needle 13
can be obtained. On the other hand, when plastic is used, an
elastic blood collection needle 13 can be obtained as well as the
needle 13 can be easily fabricated by extrusion molding, whereby
needle-stick accidents to the patient can be reduced.
[0111] Further, when the side surface of the blood collection
needle is triangular in shape, the thickness of the front end
portion 31a is increased, whereby the strength of the tip of the
blood collection needle 13a can be increased. Further, since an
apex of the triangular shape of the side surface corresponds to the
front end portion 31a, the needle tip becomes sharper and easy to
run into the skin, and moreover, incorporation of the needle 13a
into the spacer 23 constituting the sensor 11 can be
facilitated.
[0112] When the side surface of the blood collection needle is
circular in shape, it becomes unnecessary to pay attention to the
rotation direction when the blood collection needle is incorporated
in the spacer 23 constituting the blood sensor 11, and further,
fabrication is facilitated.
[0113] When the side surface of the blood collection needle is
rectangular in shape, the thickness of the front end portion 31c is
increased, whereby the strength of the tip of the blood collection
needle 13c is increased. Further, since an apex of the rectangular
shape of the side surface corresponds to the front end portion 31c,
the needle tip becomes sharper and easy to run into the skin, and
moreover, incorporation of the blood collection needle into the
spacer 23 constituting the blood sensor 11 is facilitated.
[0114] When the side surface of the blood collection needle is
hexagonal in shape, incorporation of the blood collection needle
13d into the spacer 23 constituting the blood sensor 11 is
facilitated.
Embodiment 3
[0115] FIGS. 5(a)-5(d) are plan views of a substrate 22, a spacer
23, and a cover 24 which constitute a blood sensor 11 according to
a third embodiment of the present invention, before disconnection
of a blood collection needle cover. The same components are given
the same reference numerals to simplify the description.
[0116] FIG. 5(a) is a plan view of a cover 24 and a blood
collection needle cover 32 connected to the cover 24, before
disconnection of the needle cover 32, in the blood sensor 11
according to the third embodiment. The blood collection needle
cover 32 is formed of the same material as and integrally with the
cover 24.
[0117] To be specific, the blood collection needle cover 32 is
formed so as to cover a front end portion 24c of the cover 24, and
is connected to the cover 24 at both ends 32a and 32b of the
circular front end portion 24c of the cover 24.
[0118] Further, a notch 32c is formed at a position in the blood
collection needle cover 32 corresponding to the blood collection
needle 13 so that the needle 13 is inserted into the notch 32c with
clearance. The notch 32c is a part of the blood collection needle
cover 32 that protects the blood collection needle 13.
[0119] FIG. 5(b) is a plan view of a spacer 23 and a blood
collection needle cover 33 connected to the spacer 23, before
disconnection of the needle cover 33. The blood collection needle
cover 33 is formed of the same material as and integrally with the
spacer 23.
[0120] To be specific, the blood collection needle cover 33 is
formed so as to cover a front end portion 23c of the spacer 23, and
is connected to the spacer 23 at both ends 33a and 33b of the
circular front end portion 23c of the spacer 23.
[0121] Further, a notch 33c is formed at a position in the blood
collection needle cover 33 corresponding to the blood collection
needle 13 so that the needle 13 is inserted into the notch 33c with
clearance. The notch 33c is a part of the blood collection needle
cover 33 that protects the blood collection needle 13.
[0122] FIG. 5(c) is a plan view of a substrate 22 and a blood
collection needle cover 34 connected to the substrate 22, before
disconnection of the needle cover 34, in the blood sensor 11
according to the third embodiment. The blood collection needle
cover 34 is formed of the same material as and integrally with the
substrate 22.
[0123] To be specific, the blood collection needle cover 34 is
formed so as to cover a front end portion 22c of the substrate 22,
and is connected to the substrate 22 at both ends 34a and 34b of
the circular front end portion 22c of the substrate 22.
[0124] Further, a notch 34c is formed at a position in the blood
collection needle cover 34 corresponding to the blood collection
needle 13 so that the needle 13 is inserted into the notch 34c with
clearance. The notch 34c is a part of the blood collection needle
cover 34 that protects the blood collection needle 13.
[0125] The substrate 22 before disconnection of the blood
collection needle cover 34, the spacer 23 before disconnection of
the blood collection needle cover 33, and the cover 24 before
disconnection of the blood collection needle cover 32 are laminated
and adhered to each other, resulting in a blood sensor 11 having a
blood collection needle cover 35 with a notch 35c as shown in FIG.
5(d).
[0126] The blood collection needle cover 35 is disconnected just
before use of the blood sensor 11 to expose the blood collection
needle 13.
[0127] Accordingly, the patient is not punctured with the blood
collection needle 13 before use of the blood sensor 11, and whereby
safety is secured.
[0128] According to the blood sensor 11 of the third embodiment,
the blood collection needle cover 32 is formed of the same material
as and integrally with the cover 24 as shown in FIG. 5(a), the
blood collection cover 33 is formed of the same material as and
integrally with the spacer 23 as shown in FIG. 5(b), and further,
the blood collection needle cover 34 is formed of the same material
as and integrally with the substrate 22 as shown in FIG. 5(c), and
a notch is formed in a portion of each blood collection needle
cover 13 corresponding to the blood collection needle 13 so that
the blood collection needle 13 is inserted into the notch with
clearance, which notch is a part of a blood collection needle cover
unit that protects the blood collection needle 13. Since the blood
collection needle cover unit is disconnected just before use of the
blood sensor 11 to expose the blood collection needle 13, the
patient is not punctured with the needle 13 before use of the blood
sensor 11, resulting in a safe and favorable blood sensor.
Embodiment 4
[0129] FIG. 6 is a diagram illustrating a production process of a
blood sensor 11 according to a fourth embodiment of the present
invention. The same components are given the same reference
numerals to simplify the description.
[0130] In FIG. 6, reference numeral 36 denotes a reagent
application step of applying a reagent 25 on the substrate 22 where
the detection electrodes 18.about.21 are disposed.
[0131] Reference numeral 37 denotes a bonding step of bonding the
spacer 23 and the cover 24 to each other.
[0132] Reference numeral 38 denotes a blood collection needle
attachment step of attaching the blood collection needle after the
bonding step 37.
[0133] Finally, reference numeral 39 denotes a completion step of
bonding the substrate 22 on which the reagent 25 is applied in the
reagent application step 36 to the spacer 23 and the cover 24 to
which the blood collection needle 13 is attached in the blood
collection needle attachment step 38.
[0134] In these steps, the operations are carried out in the state
where the blood collection needle covers 32, 33, and 34 described
in the third embodiment are connected.
[0135] As described above, the blood sensor fabrication method
according to the fourth embodiment comprises the reagent
application step 36 of applying the reagent 25 on the substrate 22
where the detection electrodes 18.about.21 are disposed, the
bonding step 37 of bonding the spacer 23 and the cover 24 to each
other; the blood collection needle attachment step 38 of attaching
the blood collection needle after the bonding step 37, and the
completion step 39 of bonding the substrate 22 on which the reagent
25 is applied in the reagent application step 36 to the spacer 23
and the cover 24 to which the blood collection needle 13 is
attached in the blood collection needle attachment step 38.
Therefore, it is possible to easily fabricate the blood sensor
11.
Embodiment 5
[0136] FIG. 7 is a plan view of a blood sensor 41 according to a
fifth embodiment of the present invention. In FIG. 7, the same
reference numerals as those shown in FIGS. 1 to 6 denote the same
components, and therefore, repeated description is not
necessary.
[0137] The blood sensor 41 according to the fifth embodiment is
different from the blood sensor 11 according to the first
embodiment in that two blood collection needles 13 are attached to
a front end portion 41c of the blood sensor 41 side by side and in
parallel with each other.
[0138] A supply path 42 is connected to the two blood collection
needles 13, respectively.
[0139] According to the blood sensor 41 of the fifth embodiment,
since the two blood collection needles 13 are disposed side by side
and in parallel with each other, the time for blood collection can
be reduced.
[0140] Further, even when there occurs insufficient aspiration of
blood or clogging of one needle, the blood can be supplied from the
other needle, resulting in a safe and highly-reliable blood
sensor.
Embodiment 6
[0141] FIG. 8 is a plan view of a blood sensor 45 according to a
sixth embodiment of the present invention. In FIG. 8, the same
reference numerals as those shown in FIGS. 1 to 7 denote the same
components, and therefore, repeated description is not
necessary.
[0142] The blood sensor 45 is a kind of an optical sensor, and the
degree of color change in a detection part 46 is converted into a
blood glucose level by measuring an absorbance.
[0143] For this purpose, at least one of an upper surface and a
lower surface of the detection part 46 is formed of a transparent
material, and detection light is applied to the detection part 46
through the transparent material, and the degree of light change is
read from the reflected light.
[0144] As described above, since the blood sensor according to the
sixth embodiment reads the degree of light change from the
reflected light, the contact electrodes 18a to 21a described for
the first embodiment can be dispensed with.
[0145] Accordingly, the size of the blood sensor 45 can be reduced
by just that much.
Embodiment 7
[0146] FIG. 9 is a perspective plan view of a blood sensor 11
according to a seventh embodiment of the present invention. In FIG.
9, the same components as those described with respect to the first
embodiment are given the same reference numerals to simplify the
description.
[0147] On the substrate 22, the detection electrodes 18, 19, 20,
and 21 are disposed, and these detection electrodes 18.about.21
function as, for example, a working electrode, a sensing electrode,
a counter electrode, and a hematocrit electrode, respectively.
[0148] These detection electrodes 18, 19, 20, and 21 are connected
to the contact electrodes 18a, 19a, 20a, and 21a that are disposed
on the other end 22d of the substrate 22, respectively. While in
the following description the detection electrode 21 is used for
detecting a Hct (hematocrit) value, the detection electrode 21 may
be used for measuring, not only a Hct value, but also an amount of
interfering substance that adversely affects the analytical
value.
[0149] Next, a description will be given of the construction of the
blood testing apparatus 50 according to the seventh embodiment,
with reference to FIGS. 10(a)-10(e) and 11.
[0150] FIGS. 10(a)-10(e) are cross-sectional views specifically
illustrating the blood sensor 11 and the blood sensor insertion
part of the blood testing apparatus 50 according to the seventh
embodiment, and FIG. 11 is a block diagram illustrating the entire
structure of the blood testing apparatus 50. Id these figures, the
same components are given the same reference numerals to simplify
the description.
[0151] In FIG. 10(a), reference numeral 61 denotes a cylindrical
casing, and the casing 61 includes a slider 62 that is disposed
slidably in an anteroposterior direction (horizontal direction in
the figure). Reference numeral 63 denotes a coil spring that is
fixed to the casing 61, and the coil spring 63 pushes the slider 62
forward. Reference numeral 64a denotes a blood sensor insertion
port, and this insertion port 64a is disposed at a front end of the
slider 62. An insertion path 64 is connected to the insertion port
64a. Further, contact terminals 65, 66, 67, and 68 to be connected
to the contact electrodes 18a, 19a, 20a, and 21a provided on the
blood sensor 11 are disposed in the inner part of the insertion
path 64.
[0152] Reference numeral 35 denotes a blood collection needle cover
that covers the blood collection needle 13 of the blood sensor
11.
[0153] Reference numeral 69 denotes a cylindrical cap that covers
the blood sensor 11, and its front and rear ends are opened. The
cap 69 is put on the front end of the casing 61. Reference numeral
70 denotes a hollow tube having elasticity. An end of the tube 70
is connected to an upper portion of the insertion path 64 so that
it is attached tightly to the inlet of the negative pressure
generation part 17 provided on the upper surface of the blood
sensor 11 when the blood sensor 11 is inserted.
[0154] Reference numeral 71 denotes an O ring formed of rubber
having elasticity. This O ring 71 fixes an end of the tube 70 to
the slider 62, and also improves the degree of attachment to the
inlet of the negative pressure generation part 17. The other end of
the tube 70 is connected to a first negative pressure generator 72.
The first negative pressure generator 72 has a function of reducing
the pressure in the hollow portion of the blood collection needle
13.
[0155] Reference numeral 73 denotes a tube an end of which is fixed
to the casing 61, and the other end of this tube 73 is connected to
a second negative pressure generator 74.
[0156] The second negative pressure generator 74 has a function of
reducing the pressure in the casing 61 including the cap 69.
Reference numeral 75 denotes a Lansing button (used as an example
of a blood collection button) that makes the slider 62 protrude
forward.
[0157] Further, reference numerals 65.about.68 denote contact
terminals to be connected to the contact electrodes 18a.about.21a
of the blood sensor 11, respectively.
[0158] As shown in FIG. 11, the contact terminals 65.about.68 are
connected to a switching circuit 101, and an output of the
switching circuit 101 is connected to an input of a current/voltage
converter (I/V converter) 102.
[0159] An output of the I/V converter 102 is connected to an input
of an operation unit 104 through an analog/digital converter (A/D
converter) 103.
[0160] An output of the operation unit 104 is connected to a
display unit 105 comprising liquid crystal.
[0161] Further, a reference voltage supply 108 is connected to the
switching circuit 101. The reference voltage supply 108 may be a
ground voltage.
[0162] Reference numeral 106 denotes a control unit, and an output
of the control unit 106 is connected to a control terminal of.the
switching circuit 101, the operation unit 104, a timer 109, the
first negative pressure generator 72, the second negative pressure
generator 74, and a vibration generator 77.
[0163] An output of the vibration generator 77 is connected to the
slider 62. The vibration generator 77 vibrates the slider 62,
thereby to vibrate the blood collection needle 13 of the blood
sensor 11.
[0164] Hereinafter, a description will be given of the operation of
the blood testing apparatus 50 according to the seventh embodiment
constituted as mentioned above, with reference to FIGS.
10.about.12. FIG. 12 is a flowchart illustrating a sequence of
operations of the blood testing apparatus according to the seventh
embodiment.
[0165] With reference to FIG. 12, initially, step 81 of attaching
the blood sensor 11 to the blood testing apparatus 50 will be
described.
[0166] The attachment step 81 corresponds to FIG. 10(a).
[0167] That is, the attachment step 81 includes step 82 of removing
the cap 69 from the casing 61.
[0168] In step 83 that follows step 82, the blood sensor 11 is
inserted in the insertion path 64 of the slider 62.
[0169] In this insertion step 83, the blood sensor 11 is inserted
against the force applied by the coil spring 63, whereby the slider
62 is pressed into an inner part 61a of the casing 61.
[0170] That is, the slider 62 is set in a shoot position.
[0171] It is possible to detect whether the slider 62 is set at the
shoot position or not, by checking whether the slider 62 is locked
by the Lansing button 75 or not.
[0172] That is, when the slider 62 is locked, the hand of the user
that pushes the slider 62 feels no resistance by the coil spring
63, whereby the user can sense that the slider 62 is set at the
shoot position.
[0173] Further, it is possible to detect that the blood sensor 11
is attached to the slider 62, by detecting that the contact
electrodes 18a.about.21a of the blood sensor 11 contact the contact
terminals 65.about.68, respectively.
[0174] When the blood sensor 11 is attached to the slider 62, an
end of the tube 70 is closely attached to the inlet of the negative
pressure generation part 17.
[0175] Since the tube 70 connected to the first negative pressure
generator 72 is closely attached to the inlet of the negative
pressure generation part 17, it is possible to facilitate blood
collection by reducing the pressure in the follow part of the blood
collection needle 13.
[0176] As described above, in step 83, the blood sensor 11 is
attached to the slider 62, and the slider 62 is set at the shoot
position, and thereafter, the operation goes to step 84.
[0177] In step 84, the blood collection needle cover 35 of the
blood sensor 11 is removed. Thereby, the blood collection needle 13
is exposed for the first time. Since the blood collection needle 13
has been covered with the blood collection needle cover 35 up to
step 83, safety is ensured.
[0178] Next, the operation goes to step 85. In step 85, the cap 69
is attached to the casing 61.
[0179] In this state, the blood collection needle 13 is positioned
behind the front end opening 69a of the cap 69.
[0180] The attachment step 81 of attaching the blood sensor 11 to
the blood testing apparatus 50 is completed in step 85.
[0181] Since the cap 69 is put on the blood sensor 11 when the
attachment step 81 is ended, the blood collection needle 13 is not
exposed, whereby safety is secured and the patient is not scared by
the needle 13.
[0182] Moreover, since the cap 69 is attached, even when the blood
testing apparatus 50 is dropped to the floor or the like, there
occurs no accident such as breakage of the blood collection needle
13.
[0183] Next, a description will be given of puncture preparation
step 86. FIG. 10(b) corresponds to the puncture preparation
step.
[0184] That is, in the puncture preparation step 86, initially, the
front end opening 69a of the cap 69 is pressed against skin 76 of a
measurement site so that the cap 69 closely contact the skin 76, in
step 87. Next, in step 88, the pressure in the cap 69 is reduced by
using the second negative pressure generator 74.
[0185] Thereby, the skin 76 is tensed and plumped up.
[0186] At this time, it is possible to perform the pressure
reduction by using both the first negative pressure generator 72
and the second negative pressure generator 74. The pressure
reduction is performed to reach a predetermined pressure level,
thereby completing the puncture preparation step 86.
[0187] Next, a description will be given of puncture operation step
89. FIG. 10(c) corresponds to the puncture operation step 89.
[0188] That is, in the puncture operation step 89, the Lansing
button 75 is pressed. Then, the lock mechanism is released, and the
blood sensor 11 that is pushed back by the coil spring 63 is
swiftly shot toward the plumped-up portion 76a of the skin 76,
together with the slider 62.
[0189] At this time, since the plumped-up portion 76a of the skin
76 is tensed by the second negative pressure generator 74, even
when a plastic needle 13 having elasticity is used, the needle 13
can easily run into the skin 76.
[0190] At this time, the front end of the blood collection needle
13 protrudes from the front end opening 69a of the cap 69.
[0191] Next, a description will be given of blood collection step
90. FIG. 10(d) corresponds to this blood collection step 90.
[0192] That is, in the blood collection step 90, initially, the
skin 76 of the patient is punctured with the blood collection
needle 13 in step 91, and in this state, the vibration generator 77
is driven and the first negative pressure generator 72 is also
driven, whereby the pressure in the hollow part of the blood
collection needle 13 is reduced from the negative pressure
generation part 17 of the blood sensor 11 to perform aspiration of
blood.
[0193] In this way, since the first negative pressure generator 72
is driven, the hollow part of the blood collection needle 13 is
depressurized, whereby blood collection is facilitated. Further,
since the vibration generator 77 is driven, blood collection is
further facilitated.
[0194] Furthermore, in the blood testing apparatus 50, the
switching circuit 101 is controlled according to an instruction of
the control unit 106 so that the detection electrode 18 that serves
as a working electrode to measure an amount of blood component is
connected to the I/V converter 102 through the contact terminal 65,
and the detection electrode 19 that serves as a sensing electrode
to sense a flow of blood is connected to the reference voltage
supply 108 through the contact terminal 66.
[0195] A constant voltage is applied between the detection
electrode 10 and the detection electrode 19.
[0196] In this state, when the blood reaches the detection
electrode 19 of the blood sensor 11, current flows between the
detection electrodes 18 and 19. The current flowing between the
detection electrodes 18 and 19 is converted into voltage by the I/V
converter 102, and the voltage value is converted into a digital
value by the A/D converter 103 to be outputted to the operation
unit 104.
[0197] Then, the operation unit 104 detects that the blood flows
into the blood sensor 11, on the basis of the digital value.
[0198] Also in the following step 92, collection of blood from the
skin 76 is easily carried out due to aspiration by the negative
pressure generating operation and vibration by the vibrating
operation.
[0199] Further, the blood collected from the blood collection
needle 13 is introduced to the detection part 16 through the supply
path 15 due in part to capillary phenomenon.
[0200] When the blood introduced to the detection part 16 reaches
the detection electrode 19 as a sensing electrode, the current that
flows between the detection electrodes 18 and 19 is detected by the
operation part 104 as described above, whereby it is judged that a
sufficient amount of blood to be measured is introduced, followed
by step 93.
[0201] Since blood collection is stopped when the collected blood
reaches the detection electrode 19, collection of excess blood is
prevented, i.e., a minimum necessary amount of blood is collected,
whereby the burden on the patient is minimized.
[0202] In step 93, the operations of the first negative pressure
generator 72, the second negative pressure generator 74, and the
vibration generator 77 are stopped.
[0203] When the first negative pressure generator 72 is stopped,
the blood that flows inward from the blood collection needle 13 is
prevented from flowing from the negative pressure generation part
17 toward the tube 70.
[0204] That is, the collected blood is prevented from leaking out
of the blood sensor 11.
[0205] When the second negative pressure generator 74 is stopped to
open the inside of the cap 69 to atmosphere pressure, the
plumped-up portion 76a of the skin 76 disappears, and the skin 76
turns back.
[0206] After the skin 76 turns back, the blood collection needle 13
is removed. On the other hand, if the collected blood does not
reach the detection electrode 19 that senses flow of blood in step
92, it means shortage of analyte (blood), and further aspiration of
blood is carried out in step 91.
[0207] At this time, if the blood does not reach the detection
electrode 19 even when a predetermined period of time has passed,
the blood testing apparatus 50 displays "error", and stops further
aspiration of blood.
[0208] The blood collection step 90 may be altered such that blood
collection is carried out after removing the needle 13 from the
skin 76 as shown in FIG. 10(e), while in FIG. 10(d) it is carried
out with the needle 13 being inserted in the skin 76.
[0209] That is, in step 90, after the skin 76 of the patient is
punctured with the blood collection needle 13 in the puncture step
89, the needle 13 is immediately taken out of the skin 76.
[0210] Then, the first and second negative pressure generators 72
and 74 are operated, and the patient waits in this state until
blood spills out of the punctured skin 76.
[0211] After a predetermined period of time has passed, blood
spills out of the skin 76 as shown in FIG. 10(e), and then the
blood collection needle 13 is moved to a position where the needle
tip contacts the blood. Thereby, the blood collected by the needle
13 can be introduced to the detection part 16 through the supply
path 15.
[0212] When the blood collection step 90 is completed, the
operation goes to blood glucose level measurement step 94.
[0213] In the blood glucose level measurement step 94, initially,
an amount of glucose is measured in step 95.
[0214] Measurement of an amount of glucose is carried out as
follows. After glucose in blood and glucose oxidation-reduction
enzyme are reacted for a predetermined period of time, voltage is
applied between the detection electrode 18 as a working electrode
and the detection electrode 20 as a counter electrode.
[0215] To be specific, in step 95, initially the switching circuit
101 is controlled according to an instruction of the control unit
106 so that the detection electrode 18 that serves as a working
electrode for measuring an amount of glucose is connected to the
I/V converter 102 through the contact terminal 65, and the
detection electrode 20 that serves as a counter electrode for
measuring an amount of glucose is connected to the reference
voltage supply 108 through the contact terminal 67.
[0216] While the glucose in blood and the glucose
oxidation-reduction enzyme are reacted for a predetermined period
of time, the I/V converter 102 and the reference voltage supply 108
are turned off. After a predetermined period of time (1.about.10
sec) has passed, constant voltage (0.2.about.0.5V) is applied
between the detection electrodes 10 and 20 for a predetermined
period of time (1.about.5 sec) under instruction of the control
unit 106. The reaction time and the voltage application time are
measured by a timer 109.
[0217] Then, the mediator in the reduced state, which occurs on the
detection electrode 18 by enzyme reaction, is oxidized, and the
oxidation current is detected between the detection electrodes 18
and 20.
[0218] This current is converted into voltage by the I/V converter
102, and the voltage value is converted into a digital value by the
A/D converter 103 to be outputted to the operation unit 104.
[0219] The operation unit 104 converts the digital value into an
amount of glucose.
[0220] Next, measurement of Hct value is carried out in step
96.
[0221] Initially, the switching circuit 101 is controlled according
to an instruction of the control unit 106 so that the detection
electrode 21 that serves as a working electrode for measuring a Hct
value is connected to the I/V converter 102 through the contact
terminal 68, and the detection electrode 18 that serves as a
counter electrode for measuring a Hct value is connected to the
reference voltage supply 108.
[0222] Then, according to an instruction of the control unit 106, a
constant voltage (2V.about.3V) is applied between the detection
electrodes 21 and 18 from the I/V converter 102 and the reference
voltage supply 108.
[0223] Thereby, current that depends on the Hct value is detected
between the detection electrodes 21 and 18.
[0224] The current that flows between the detection electrodes 21
and 18 is converted into voltage by the I/V converter 102, and the
voltage value is converted into a digital value by the A/D
converter 103 to be outputted to the operation unit 104.
[0225] The operation unit 104 calculates a Hct value on the basis
of the digital value.
[0226] This Hct value is used for correction during glucose
measurement.
[0227] This correction may use a Hct value which is obtained from a
previously formed analytical curve between current and Hct value.
Alternatively, the detected current may be used as it is.
[0228] In step 96, the applied voltage is 2.about.3V, and the
application time is 0.01.about.5 sec.
[0229] In step 96, no mediator is disposed on the detection
electrode 21 as a working electrode, the detection electrodes 21
and 18 are separated at an interval, and only blood exists in this
interval. Therefore, it is possible to detect oxidation current
that depends on the Hct value, without being affected by the
reagent 25.
[0230] Finally, the blood component is corrected in step 97. That
is, the amount of glucose obtained in step 95 is corrected using
the Hct value detected in step 96.
[0231] This correction is carried out on the basis of a previously
formed analytical curve (including an analytical table).
[0232] The corrected amount of glucose is displayed on the display
unit 105 of the blood testing apparatus 50.
[0233] The used blood sensor 11 after completion of the blood
glucose level measurement step 94 is discarded every time a
measurement is ended.
[0234] In the above-described blood testing apparatus 50 that
measures blood glucose level using the blood sensor 11 according to
the seventh embodiment, the blood sensor 11 is attached to the
slider 26 included in the blood testing apparatus 50, and the cap
69 is attached to the casing 61, and then the target site is
punctured with the blood collection needle 13 that is provided on
the blood sensor 11. Thereafter, the hollow part of the needle 13
is depressurized by the negative pressure generation part 17 an end
of which is connected to the first negative pressure generator 72
to facilitate collection of blood, the collected blood is guided to
the detection part 16 through the supply path 15, the component of
the blood guided to the detection part 16 is reacted with a reagent
to generate current, and detection of blood glucose level is
carried out on the basis of the generated current. Therefore,
puncture and blood collection can be simultaneously carried out by
using the blood collection needle 13, and further, the collected
blood can be tested as it is in the blood testing apparatus 50
without intervening manual work.
[0235] Further, since the cap 69 is attached to the blood sensor 11
when blood collection is carried out by using the blood collection
needle 13, the blood collection needle 13 is not exposed, whereby
safety is secured and the patient is not scared by the needle 13.
Further, even when the blood testing apparatus 50 is dropped to the
floor or the like, there occurs no accident such as breakage of the
blood collection needle 13.
[0236] Further, when performing the blood collection, the front end
opening 69a of the cap 69 is pressed against the skin 76 of the
target site, and then the inside of the cap 69 is depressurized by
the second negative pressure generator 74 so that the skin 76 is
tensed and plumped up, and thereafter, the plumped-up portion 76a
of the skin 76 is punctured with the blood collection needle 13.
Therefore, the puncture is facilitated.
[0237] Moreover, during the blood collection, since the first
negative pressure generator 72 and the vibration generator 77 are
driven, the blood collection is further facilitated.
[0238] When the blood that is guided to the detection part 16
through the supply path 15 reaches the detection electrode 19 as a
sensing electrode, it is judged that a necessary amount of blood is
supplied, and thereby the blood collection is completed. Therefore,
a minimum necessary amount of blood can be collected without
collecting an excess amount of blood, whereby the burden on the
patient can be minimized.
[0239] Moreover, while in the above-description the blood
collection is carried out with the needle 13 being inserted in the
skin 76, blood collection may be carried out as follows. That is,
the needle 13 is taken out of the skin 76 of the patient
immediately after the skin 76 is punctured with the blood
collection needle 13 in the puncture step 89, and the patient waits
for a while until blood spills out of the punctured skin 76 with
the first and second negative pressure generators being
continuously driven, and the blood collection needle 13 is moved to
a position where the needle tip contacts the blood when the blood
spills out of the skin 76, thereby collecting the blood. Thus, the
burden on the patient can be further reduced.
Embodiment 8
[0240] FIG. 13 is a block diagram illustrating a blood testing
apparatus 50a according to an eighth embodiment of the present
invention.
[0241] With reference to FIG. 13, reference numeral 107 denotes a
transmission unit for transmitting a measured value obtained by the
blood testing apparatus 50 to an external device. The transmission
unit 107 is connected to the control unit 106 and the operation
unit 104.
[0242] Next, a description will be given of the operation of the
blood testing apparatus 50a using the blood sensor 11 according to
the eighth embodiment.
[0243] Initially, the switching circuit 101 is controlled according
to an instruction of the control unit 106 so that the detection
electrode 18 that serves as a working electrode to measure an
amount of blood component is connected to the I/V converter 102
through the contact terminal 65.
[0244] Further, the detection electrode 19 that serves as a sensing
electrode to sense flow of blood is connected to the reference
voltage supply 108 through the contact terminal 66.
[0245] Then, a constant voltage is applied between the detection
electrodes 18 and 19.
[0246] In this state, when blood is introduced, current flows
between the detection electrodes 18 and 19. The current is
converted into voltage by the I/V converter 102, and the voltage
value is converted into a digital value by the A/D converter 103 to
be outputted to the operation unit 104. In the operation unit 104,
it is detected that blood flows in on the basis of the digital
value.
[0247] Next, measurement of glucose as a blood component is carried
out.
[0248] Initially, the switching circuit 101 is controlled according
to an instruction of the control unit 106 so that the detection
electrode 18 that serves as a working electrode to measure an
amount of glucose is connected to the I/V converter 102 through the
contact terminal 65.
[0249] Further, the detection electrode 20 that serves as a counter
electrode to measure an amount of glucose is connected to the
reference voltage supply 108 through the contact terminal 67.
[0250] The I/V converter 102 and the reference voltage supply 108
are turned off during a predetermined period of time wherein the
glucose in blood and an oxidation-reduction.enzyme are reacted to
each other. After a predetermined period of time (1.about.10 sec)
has passed, a constant voltage (0.2.about.0.5V) is applied between
the detection electrodes 18 and 20 under instruction of the control
unit 106.
[0251] In this state, when reaction occurs, current flows between
the detection electrodes 18 and 20, and this current is converted
into voltage by the I/V converter 102, and further, the voltage
value is converted into a digital value by the A/D converter 103 to
be outputted to the operation unit 104. In the operation unit 104,
the digital value is converted into an amount of glucose.
[0252] After the amount of glucose is measured, measurement of a
Hct value is carried out.
[0253] Initially, the switching circuit 101 is controlled according
to an instruction of the control unit 106 so that the detection
electrode 21 that serves as a working electrode to measure a Hct
value is connected to the I/V converter 102 through the contact
terminal 68.
[0254] Further, the detection electrode 18 that serves as a counter
electrode to measure a Hct value is connected to the reference
voltage source 108.
[0255] Then, according to an instruction from the control unit 106,
a constant voltage (2V.about.3V) is applied between the detection
electrodes 21 and 18 from the I/V converter 102 and the reference
voltage supply 108.
[0256] The current flowing between the detection electrodes 21 and
18 is converted into voltage by the I/V converter 102, and the
voltage value is converted into a digital value by the A/D
converter 103 to be outputted to the operation unit 104.
[0257] The operation unit 104 converts the digital value into a Hct
value.
[0258] With reference to an analytical curve or an analytical curve
table which has previously been obtained using the measured Hct
value and the amount of glucose component, the amount of glucose
component is corrected with the Hct value, and the result of
correction is displayed on the display unit 105.
[0259] Further, the corrected result is transmitted from the
transmission unit 107 toward an injection unit (not shown) for
injecting insulin (an example of curative).
[0260] Although this transmission may use radio wave, optical
communication that has no interference to medical equipment is
preferable.
[0261] Since the measured data thus corrected is transmitted from
the transmission unit 107, a dose of insulin is automatically set
in the injection unit.
[0262] Accordingly, the patient is saved from the trouble of
setting the dose of insulin to be administered, on the injection
unit.
[0263] Further, since the dose of insulin is set on the injection
unit without intervening artificial means, setting error can be
avoided.
[0264] In the blood testing apparatus 50a using the blood sensor 11
according to the eighth embodiment of the present invention, since
the data measured and corrected by the blood testing apparatus 50a
is transmitted from the transmission unit 107 to an external device
such as an insulin injection unit, the dose of insulin can be
automatically set on the injection unit. Therefore, it is not
necessary for the patient to set the dose of insulin on the
injection unit, whereby the patient is saved from the trouble of
setting the same. Further, since the dose of insulin is set on the
injection unit without intervening artificial means, setting error
can be avoided.
[0265] While in the embodiments of the present invention
measurement of glucose has been described, the present invention is
also applicable to measurement of blood components such as lactic
acid and cholesterol.
APPLICABILITY IN INDUSTRY
[0266] Since a blood sensor according to the present invention can
easily perform blood test, it is applicable to a blood testing
apparatus and the like.
* * * * *