EP0875201A1
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EP
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Noninvasive blood examination apparatus
Assignee: ISHIHARA, KEN
•
Filing: 1996-12-27
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Granted: —
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Expires: 2016-12-27
Abstract
Abstract A noninvasive blood analyzer is provided which comprises: a light source for illuminating a part of tissues of a living body including a blood vessel; an image pickup section for picking up an image of the illuminated blood vessel and tissues; and an analyzing section for analyzing the picked image; the analyzing section including an extracting section for extracting image density distribution across the blood vessel in the picked image as an image density profile, a quantifying section for quantifying configurational characteristics of the image density profile, a computing section for computing the concentration of a blood constituent on the basis of the quantified characteristics, and an outputting section for outputting a computation result. The blood analyzer can measure the concentration of blood hemoglobin and the hematocrit in real time with an improved repeatability without blood sampling.
Inventors
- 👤 Ken Ishihara
- 👤 Kaoru Asano
- 👤 Yasuhiro Kouchi
- 👤 Hideo Kusuzawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 13:46
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/145; A61B5/14535; A61B5/1455; A61B5/14551; A61B5/14552; A61B5/68; A61B5/6801; A61B5/6813; A61B5/6825; A61B5/6826; A61B5/683; A61B5/6838; G; G01; G01N; G01N21/00; G01N21/17; G01N21/47; G01N21/4795
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
112 words
A noninvasive blood analyzer comprising: a light source for illuminating a part of tissues of
a living body including a blood vessel; an image pickup section for picking up an image of
the illuminated blood vessel and tissues; and an analyzing section for analyzing the picked image,
wherein the analyzing section includes: an extracting section for extracting image density
distribution across the blood vessel in the picked image as
an image density profile; a quantifying section for quantifying
configurational characteristics of the image density
profile; a computing section for computing an amount of a
blood constituent on the basis of the quantified
characteristics; and an outputting section for outputting the computed
amount.
Claim 2
Dependent Claim
26 words
A noninvasive blood analyzer as set forth in claim
1, wherein the amount of the blood constituent is at least
one of hemoglobin concentration and hematocrit.
Claim 3
Dependent Claim
41 words
A noninvasive blood analyzer as set forth in claim
1, wherein the light source comprises a light emitting
device which is adapted to selectively emit light beams of
first and second wavelengths, which are substantially
isosbestic for oxidized and reduced hemoglobins.
Claim 4
Dependent Claim
43 words
A noninvasive blood analyzer as set forth in claim
1, wherein the extracting section searches for an area in
the image where a blood vessel image stands in the sharpest
contrast and extracts the image density profile from the
area thus searched for.
Claim 5
Dependent Claim
44 words
A noninvasive blood analyzer as set forth in claim
1, wherein the quantifying section normalizes the image
density profile, and computes a peak value h and a
distribution width w corresponding to the diameter of the
blood vessel from the normalized image density profile.
Claim 6
Dependent Claim
102 words
A noninvasive blood analyzer as set forth in claim
5, wherein the light source comprises a light emitting
device which is adapted to selectively emit light beams of
first and second wavelengths; wherein the quantifying section computes peak values
h1 and h2 and distribution widths w1 and w2 of first and
second profiles respectively obtained by picking up images
of the same part of the body tissues at the first and second
wavelengths; and wherein the computing section computes the
concentration of hemoglobin and hematocrit on the basis of
the computed peak values h1 and h2 and distribution widths
w1 and w2.
Claim 7
Dependent Claim
77 words
A noninvasive blood analyzer as set forth in claim
6, wherein the quantifying section estimates a depth L at
which the blood vessel is located on the basis of the
distribution widths w1 and w2 of the first and second image
density profiles obtained by picking up images of the same
part of the body tissues at the first and second
wavelengths, and corrects the peak values h1 and h2 on the
basis of the depth L.
Claim 8
Dependent Claim
47 words
A noninvasive blood analyzer as set forth in claim
2, wherein the image pickup section includes an object lens,
a focusing lens, a space filter disposed between the lenses
and having two-dimensionally variable transmittances, and
filter controlling means for two-dimensionally varying the
transmittance of the space filter.
Claim 9
Dependent Claim
37 words
A noninvasive blood analyzer as set forth in claim
8, wherein the image pickup section further includes
adjusting means for adjusting the position of a focal point
of the object lens with respect to the blood vessel.
Claim 10
Dependent Claim
44 words
A noninvasive blood analyzer as set forth in claim
9, wherein the quantifying section normalizes the image
density profile, and computes a peak value h and a
distribution width w corresponding to the diameter of the
blood vessel from the normalized image density profile.
Claim 11
Dependent Claim
77 words
A noninvasive blood analyzer as set forth in claim
10, wherein the quantifying section computes a depth L
defined between a surface of the body tissues and the blood
vessel on the basis of the position of the focal point of
the object lens which is adjusted by the adjusting means
such that the sharpest image is picked up, and corrects the
peak value h and the distribution width w on the basis of
the depth L.
Claim 12
Dependent Claim
44 words
A noninvasive blood analyzer as set forth in claim
8, wherein the quantifying section normalizes the image
density profile, and computes a peak value h and a
distribution width w corresponding to the diameter of the
blood vessel from the normalized image density profile.
Claim 13
Dependent Claim
45 words
A noninvasive blood analyzer as set forth in claim
12, wherein the quantifying section corrects the peak value
h and the distribution width w on the basis of a plurality
of images picked up every time the transmittance of the
space filter is two-dimensionally varied.
Claim 14
Dependent Claim
30 words
A noninvasive blood analyzer as set forth in claim
1, further comprising a fixing member for relatively fixing
the living body to the light source and the image pickup
section.
Claim 15
Dependent Claim
28 words
A noninvasive blood analyzer as set forth in claim
1, wherein the image pick up section picks up a transmitted
light image of the blood vessel and tissues.
Claim 16
Dependent Claim
28 words
A noninvasive blood analyzer as set forth in claim
1, wherein the image pick up section picks up a reflected
light image of the blood vessel and tissues.
Claim 17
Dependent Claim
74 words
A noninvasive blood analyzer comprising: a light source for illuminating a part of tissues of
a living body including a blood vessel; an image pickup section for picking up an image of
the illuminated blood vessel and tissues; and an analyzing section for analyzing the picked image,
the analyzing section analyzing an image of the blood vessel
in the picked image to compute an amount of a blood
constituent and output a computation result.
Claim 18
Dependent Claim
26 words
A noninvasive blood analyzer as set forth in claim
17, wherein the amount of the blood constituent is at least
one of hemoglobin concentration and hematocrit.
Claim 19
Dependent Claim
41 words
A noninvasive blood analyzer as set forth in claim
17, wherein the light source comprises a light emitting
device which is adapted to selectively emit light beams of
first and second wavelengths, which are within a range
between 600 and 950nm.
Claim 20
Dependent Claim
47 words
A noninvasive blood analyzer as set forth in claim
17, wherein the image pickup section includes an object
lens, a focusing lens, a space filter disposed between the
lenses and having two-dimensionally variable transmittances,
and filter controlling means for two-dimensionally varying
the transmittance of the space filter.
Claim 21
Dependent Claim
37 words
A noninvasive blood analyzer as set forth in claim
20, wherein the image pickup section further includes
adjusting means for adjusting the position of a focal point
of the object lens with respect to the blood vessel.
Claim 22
Dependent Claim
30 words
A noninvasive blood analyzer as set forth in claim
17, further comprising a fixing member for relatively fixing
the living body to the light source and the image pickup
section.
Claim 23
Dependent Claim
27 words
A noninvasive blood analyzer as set forth in claim
17, wherein the image pickup section picks up a transmitted
light image of the blood vessel and tissues.
Claim 24
Dependent Claim
27 words
A noninvasive blood analyzer as set forth in claim
17, wherein the image pickup section picks up a reflected
light image of the blood vessel and tissues.
References Cited (Backward Citations)
No citation records indexed.
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