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Claims  |
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What is claimed is:
1. A bilirubin concentration measuring apparatus, comprising:
(a) a light emitter for emitting a light which includes a first luminous
flux falling in a first wavelength range and a second luminous flux
falling in a second wavelength range, their bilirubin absorption
coefficients differing from each other;
(b) a light emerging port for projecting the light including the first and
second luminous fluxes from the light emitter onto skin of a person for
entering thereinto;
(c) a first light incident port for allowing the first and second luminous
fluxes having been diffused in tissues of the person to pass therethrough;
(d) a second light incident port for allowing the first and second luminous
fluxes having been diffused in tissues of the person to pass therethrough,
the second light incident port being spaced away from the light emerging
port a different distance than the first light incident port, so that
optical path length of luminous fluxes which pass through the first light
incident port and optical path length of luminous fluxes which pass
through the second light incident port are different from each other;
(e) a first electric signal generator for generating a first electric
signal corresponding to an intensity of the first luminous flux passed
through the first light incident port, and a second electric signal
corresponding to an intensity of the second luminous flux passed through
the first light incident port;
(f) a second electric signal generator for generating a third electric
signal corresponding to an intensity of the first luminous flux passed
through the second light incident port, and a fourth electric signal
corresponding to an intensity of the second luminous flux passed through
the second light incident port; and
(g) a calculator for calculating a bilirubin concentration based on the
first to fourth electric signals se that includes a processor that cancels
the influence of skin by using the luminous fluxes of the different
optical path length.
2. The apparatus according to claim 1, wherein:
the light emerging port has the form of a circle and is disposed in a
middle of a light incident plane;
the first light incident port has the form of a ring and is disposed on an
outside of the light emerging port; and
the second light incident port has the form of a ring and is disposed on an
outside of the first light incident port.
3. The apparatus according to claim 1, wherein:
the light emitter includes a white light source operable to emit white
light containing the first and second luminous fluxes;
the first signal generator includes:
a first light splitter for splitting the diffused luminous fluxes passed
through the first light incident port into the first luminous flux and the
second luminous flux;
a first photoelectric conversion device for generating the first electric
signal corresponding to the intensity of the first luminous flux split by
the first light splitter; and
a second photoelectric conversion device for generating the second electric
signal corresponding to the intensity of the second luminous flux split by
the first light splitter; and
the second signal generator includes:
a second light splitter for splitting the diffused luminous fluxes passed
through the
second light incident port into the first luminous flux and the second
luminous flux; a third photoelectric conversion device for generating the
third electric signal corresponding to the intensity of the first luminous
flux split by the second light splitter; and
a fourth photoelectric conversion device for generating the fourth electric
signal corresponding to the intensity of the second luminous flux split by
the second light splitter.
4. The apparatus according to claim 3, further comprising:
a first light guiding member for guiding the diffused luminous fluxes
passed through the first light incident port to the first light splitter;
and
a second light guiding member for guiding the diffused luminous fluxes
passed through the second light incident port to the second light
splitter.
5. The apparatus according to claim 1, further comprising:
an emission controller for controlling the emission of the light emitter,
wherein
the light emitter includes:
a first light source operable to emit the first luminous flux; and
a second light source operable to emit the second luminous flux;
the emission controller controls the first and second light sources to emit
the first and second luminous fluxes separately;
the first electric signal generator includes a first photoelectric
conversion device operable to individually generate the first and second
electric signals based on the first and second luminous fluxes separately
passed through the first light incident port; and
the second electric signal generator includes a second photoelectric
conversion device operable to individually generate the third and fourth
electric signals based on the first and second luminous fluxes separately
passed through the second light incident port.
6. The apparatus according to claim 5, further comprising:
a first light guiding member for guiding the diffused luminous fluxes
passed through the first light incident port to the first photoelectric
conversion device; and
a second light guiding member for guiding the diffused luminous fluxes
passed through the second light incident port to the second photoelectric
conversion device.
7. The apparatus according to claim 5, wherein the first light source
includes a blue light emitting diode, and the second light source includes
a green light emitting diode or a red light emitting diode.
8. The apparatus according to claim 1, wherein the first luminous flux is
absorbable by bilirubin, and the second luminous flux is hardly absorbable
by bilirubin.
9. The apparatus according to claim 1, further comprising a memory for
storing first to fourth constants corresponding to the first to fourth
electric signals, respectively, wherein the calculator executes:
calculation of first to fourth products by multiplying the first to fourth
electric signals by the first to fourth constants;
calculation of a first logarithmic number of a quotient obtained by
division of the second product by the first product;
calculation of a second logarithmic number of a quotient obtained by
division of the fourth product by the third product; and
calculation of a bilirubin concentration based on a difference between the
calculated two logarithmic numbers.
10. The apparatus according to claim 9, further comprising:
a constant calculator for calculating the first to fourth constants; and
a storage controller for controlling storage of the calculated first to
fourth constants in the memory, wherein the constant calculator calculates
the first to fourth constants to assure the following relationships:
1) a product of a first white electric signal and the first constant is
equal to a product of a second white electric signal and the second
constant; and
2) a product of a third white electric signal and the third constant is
equal to a product of a fourth white electric signal and the fourth
constant,
wherein the first to fourth white electric signals are first to second
electric signals which are obtained under conditions where the first and
second luminous fluxes are projected onto a white diffuser having no
wavelength dependency, and the first and second luminous fluxes from the
white diffuser are received after having passed through the first and
second light incident ports.
11. The apparatus according to claim 1, further comprising:
a projection operable to come into contact with skin of a person, the
projection having a light-blocked potion and a non-light-blocked portion,
wherein
the light emerging port, and the first and second light incident ports are
provided in the non-light-blocked portion of the projection.
12. A bilirubin concentration measuring apparatus, comprising:
(a) a light emitter for emitting a light which includes a first luminous
flux falling in a first wavelength range and a second luminous flux
falling in a second wavelength range, their bilirubin absorption
coefficients differing from each other;
(b) a light emerging port for projecting the light including the first and
second luminous fluxes from the light emitter onto skin of a person for
entering thereinto;
(c) a first light incident port for allowing the first and second luminous
fluxes having been diffused in tissues of the person to pass therethrough;
(d) a second light incident port for allowing the first and second luminous
fluxes having been diffused in tissues of the person to pass therethrough,
wherein the first light incident port and the second light incident port
have forms of ring or circle having relative different radii so that the
second light incident port being spaced away from the light emerging port
a different distance than the first light incident port;
(e) a first electric signal generator for generating a first electric
signal corresponding to an intensity of the first luminous flux passed
through the first light incident port, and a second electric signal
corresponding to an intensity of the second luminous flux passed through
the first light incident port;
(f) a second electric signal generator for generating a third electric
signal corresponding to an intensity of the first luminous flux passed
through the second light incident port, and a fourth electric signal
corresponding to an intensity of the second luminous flux passed through
the second light incident port; and
(g) a calculator for calculating a bilirubin concentration based on the
first to fourth electric signals.
13. The apparatus according to claim 12, wherein:
the light emitter includes a white light source operable to emit white
light containing the first and second luminous fluxes;
the first signal generator includes:
a first light splitter for splitting the diffused luminous fluxes passed
through the first light incident port into the first luminous flux and the
second luminous flux;
a first photoelectric conversion device for generating the first electric
signal corresponding to the intensity of the first luminous flux split by
the first light splitter; and
a second photoelectric conversion device for generating the second electric
signal corresponding to the intensity of the second luminous flux split by
the first light splitter; and
the second signal generator includes:
a second light splitter for splitting the diffused luminous fluxes passed
through the second light incident port into the first luminous flux and
the second luminous flux;
a third photoelectric conversion device for generating the third electric
signal corresponding to the intensity of the first luminous flux split by
the second light splitter; and
a fourth photoelectric conversion device for generating the fourth electric
signal corresponding to the intensity of the second luminous flux split by
the second light splitter.
14. The apparatus according to claim 12, further comprising:
an emission controller for controlling the emission of the light emitter,
wherein
the light emitter includes:
a first light source operable to emit the first luminous flux; and
a second light source operable to emit the second luminous flux;
the emission controller controls the first and second light sources to emit
the first and second luminous fluxes separately;
the first electric signal generator includes a first photoelectric
conversion device operable to individually generate the first and second
electric signals based on the first and second luminous fluxes separately
passed through the first light incident port; and the second electric
signal generator includes a second photoelectric conversion device
operable to individually generate the third and fourth electric signals
based on the first and second luminous fluxes separately passed through
the second light incident port.
15. The apparatus according to claim 12, wherein the first luminous flux is
absorbable by bilirubin, and the second luminous flux is hardly absorbable
by bilirubin.
16. The apparatus according to claim 12, further comprising a memory for
storing first to fourth constants corresponding to the first to fourth
electric signals, respectively, wherein the calculator executes:
calculation of first to fourth products by multiplying the first to fourth
electric signals by the first to fourth constants;
calculation of a first logarithmic number of a quotient obtained by
division of the second product by the first product;
calculation of a second logarithmic number of a quotient obtained by
division of the fourth product by the third product; and
calculation of a bilirubin concentration based on a difference between the
calculated two logarithmic numbers.
17. The apparatus according to claim 12, further comprising:
a projection operable to come into contact with skin of a person, the
projection having a lighted-blocked potion and a non-light-blocked
portion, wherein
the light emerging port, and the first and second light incident ports are
provided in the non-light-blocked portion of the projection.
18. A bilirubin concentration measuring apparatus, comprising:
a light emitter for emitting a light which includes a first luminous flux
falling in a first wavelength range and a second luminous flux falling in
a second wavelength range, their bilirubin absorption coefficients
differing from each other;
a light emerging port for projecting the first and second luminous fluxes
onto skin of a person;
a first light incident port for allowing the first and second luminous
fluxes having been diffused in the skin to pass therethrough;
a second light incident port for allowing the first and second luminous
fluxes having been diffused in the skin to pass therethrough, the second
light incident port being spaced away from the light emerging port a
different distance than the first light incident port;
a first electric signal generator for generating a first electric signal
corresponding to an intensity of the first luminous flux passed through
the first light incident port, and a second electric signal corresponding
to an intensity of the second luminous flux passed through the first light
incident port;
a second electric signal generator for generating a third electric signal
corresponding to an intensity of the first luminous flux passed through
the second light incident port, and a fourth electric signal corresponding
to an intensity of the second luminous flux passed through the second
light incident port; and
a calculator for calculating a bilirubin concentration based on the first
to fourth electric signals wherein:
the first light incident port has the form of a circle and is disposed in a
middle of a light incident plane;
the light emerging port has the form of a ring and is disposed on an
outside of the first light incident port; and
the second light incident port has the form of a ring and is disposed on an
outside of the light emerging port. |
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Claims |
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Description |
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This application is based on patent application No. 11-92632 filed in
Japan, the contents of which are hereby incorporated by references.
BACKGROUND OF THE INVENTION
This invention relates to a bilirubin concentration measuring apparatus for
transcutaneously measuring a bilirubin concentration in blood from the
outside of a skin and a measurement data checking plate used therewith.
Generally, icterus, particularly severe icterus of new-born babies may
cause a death or, even if they can escape from a death, it may progress to
nuclear icterus which causes aftereffects such as cerebral palsy. Thus,
the detection of icterus in an early stage is very crucial. The degree of
icterus should be precisely detected by measuring a bilirubin
concentration in blood serum collected from new-born babies. However, it
is difficult to collect blood from all new-born babies and to measure the
bilirubin concentration or it may bet often unnecessary.
Accordingly, the icterus of a patient has been diagnosed using an icterus
detector disclosed in, e.g., U.S. Pat. No. 4,267,844 without collection of
blood sample. This icterus detector includes a light source for emitting a
light to the skin of a human body and at least two light receiving
elements for responding to light components of the reflected light in at
least two wavelength ranges whose absorption coefficients by bilirubin
pigmented in subcutaneous fat differ from each other. The degree or stage
of icterus is measured based on the outputs of the respective light
receiving elements. In this way, the degree of icterus is indirectly
measured by measuring the concentration of bilirubin pigmented in
subcutaneous fat instead of measuring a serum bilirubin concentration.
However, since the above icterus detector measures the degree of icterus
based on the reflected light from the skin, measurement results are likely
to be influenced by a difference in the thicknesses of epidermis and derma
located above the subcutaneous tissues containing fat where bilirubin is
pigmented (e.g., a difference in the skin maturity of the new-born baby),
the skin color of a patient, i.e., a race difference. Therefore, it is
difficult to constantly and accurately measure the degree of icterus.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a transcutaneous
bilirubin concentration measuring apparatus and a measuring data checking
plate which are free of the problems residing in the prior art.
According to an aspect of the invention, a transcutaneous bilirubin
concentration measuring apparatus comprises: a light emitter for emitting
a first luminous flux falling in a first wavelength range and a second
luminous flux falling in a second wavelength range, their bilirubin
absorption coefficients differing from each other; a light emerging port
for projecting the first and second luminous fluxes onto skin of a person;
a first light incident port for allowing the first and second luminous
fluxes having been diffused in the skin to pass therethrough; a second
light incident port for allowing the first and second luminous fluxes
having been diffused in the skin to pass therethrough, the second light
incident port being spaced away from the light emerging port a different
distance than the first light incident port; a first electric signal
generator for generating a first electric signal corresponding to an
intensity of the first luminous flux passed through the first light
incident port, and a second electric signal corresponding to an intensity
of the second luminous flux passed through the first light incident port;
a second electric signal generator for generating a third electric signal
corresponding to an intensity of the first luminous flux passed through
the second light incident port, and a fourth electric signal corresponding
to an intensity of the second luminous flux passed through the second
light incident port; and a calculator for calculating a bilirubin
concentration based on the first to fourth electric signals.
According to another aspect of the invention, a transcutaneous bilirubin
concentration measuring apparatus comprises: a light emitter for emitting
a first luminous flux falling in a first wavelength range, a second
luminous flux falling in a second wavelength range, and a third luminous
flux falling in a third wavelength range, the first luminous flux being
absorbable by bilirubin, the second and third being hardly absorbable by
bilirubin; a light emerging port for projecting the first to third
luminous fluxes onto skin of a person; a light incident port for allowing
the first to third luminous fluxes having been diffused in the skin to
pass therethrough; an electric signal generator for generating first to
third electric signals corresponding to intensities of the first to third
luminous fluxes passed through the light incident port, respectively; and
a calculator for calculating a bilirubin concentration based on the first
to third electric signals.
According to still another aspect of the invention, a measurement data
checking plate is used with a transcutaneous bilirubin concentration
measuring apparatus, and comprises: a first light diffusing layer disposed
in a top part of the plate and having substantially the same absorption
coefficient for both a first luminous flux falling in a first wavelength
range and a second luminous flux falling in a second wavelength range
which are used in the bilirubin concentration measuring apparatus; and a
second light diffusing layer disposed below the first light diffusing
layer and having a higher absorption coefficient of the first luminous
flux than of the second luminous flux.
These and other objects, features and advantages of the present invention
will become more apparent upon a reading of the following detailed
description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is an entire perspective view showing an external configuration of
a transcutaneous bilirubin concentration measuring apparatus according to
a first embodiment of the invention;
FIG. 1B is an enlarged view of an projection portion of the measuring
apparatus shown in FIG. 1A;
FIG. 1C is a front view of the projection portion;
FIG. 2 is a perspective diagram showing an optical system accommodated in a
casing of the measuring apparatus shown in FIG. 1A;
FIG. 3 is a block diagram showing an electric construction of the measuring
apparatus shown in FIG. 1A;
FIG. 4 is a sectional view of a new-born baby's skin diagrammatically
showing optical paths when a light is incident on the skin;
FIG. 5 is a sectional view of new-born babies' skins diagrammatically
showing optical paths when a light is incident on the skins;
FIG. 6 is a perspective diagram showing a modification of the optical
system;
FIG. 7 is a block diagram showing an electric construction of a
transcutaneous bilirubin concentration measuring apparatus having the
optical system shown in FIG. 6;
FIG. 8 is a flowchart showing a measuring operation of the measuring
apparatus shown in FIG. 6;
FIG. 9A is a perspective view of a modification of the projection portion;
FIG. 9B is a front view of the modified projection portion;
FIG. 10 is a perspective diagram showing an optical system accommodated in
a casing having the projection portion shown in FIGS. 9A and 9B;
FIG. 11A is an entire perspective view showing a transcutaneous bilirubin
concentration measuring apparatus according to a second embodiment of the
invention;
FIG. 11B is an enlarged partial perspective view showing a projection
portion of the measuring apparatus shown in FIG. 11A;
FIG. 12 is a perspective diagram showing an optical system of the measuring
apparatus shown in FIG. 11A;
FIG. 13 is a block diagram showing an electric construction of the
measuring apparatus shown in FIG. 11A;
FIG. 14 is a modification of the optical system according to the second
embodiment;
FIG. 15 is a block diagram showing an electric construction of a
transcutaneous bilirubin concentration measuring apparatus having the
optical system shown in FIG. 14;
FIGS. 16A and 16B are sectional views showing modifications of the end face
of the projection portion, respectively;
FIGS. 17A to 17C show a measurement data checking plate according to
another embodiment of the invention, wherein FIG. 17A is a perspective
view showing an external configuration of the checking plate, FIG. 17B is
a sectional view showing an internal construction of a high concentration
testing section, and FIG. 17C a sectional view showing an internal
construction of a low concentration testing section; and
FIG. 18 is a sectional view showing a modification of the high
concentration testing section of the checking plate shown in FIGS. 17A to
17C.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
A construction of a transcutaneous bilirubin concentration measuring
apparatus according to a first embodiment of the invention will be
described with reference to FIGS. 1A to 1C. As shown in FIG. 1A, this
measuring apparatus 10 has a casing 11 of such a size holdable in hand. In
this casing 11 are arranged an optical system and electric elements to be
described later. Further, a display 12 for displaying a measurement
result, i.e., a concentration of bilirubin pigmented in subcutaneous fat
is provided at the rear end of the upper surface of the casing 11.
A cylindrical projection 13 is projectably and retractably (as indicated by
an arrow AR) mountable on the leading end of the casing 11. This
projection 13 is biased in such a direction as to project from the casing
11 (arrow direction AR) by a biasing means (not shown) such as a spring
member. When a person who conduct a measurement presses the projection 13
against a part, such as a forehead, of a person to be measured, it is
pushed into the casing 11 against a biasing force of the biasing means,
thereby driving a xenon tube 21 (see FIG. 2) described later.
In the middle of the end face of the projection 13 is provided, as shown in
FIG. 1B, a round emerging port 14 through which luminous fluxes from the
xenon tube 21 emerge out. An annular first incident port 15 is provided
outside the emerging port 14, an annular second incident port 16 is
provided outside the first incident port 15, and an annular light blocking
portion 17 is provided at the outermost. As shown in FIG. 1C, the emerging
port 14 and the first incident port 15, and the first and second incident
ports 15 and 16 are partitioned by spacers 18, 19 painted in black,
respectively. The light blocking portion 17 is applied with a matte finish
and painted in black. Consequently, no external light is incident on the
respective incident ports 15, 16.
When the projection 13 is pushed in to drive the xenon tube 21, white light
from the xenon tube 21 emerges out through the emerging port 14 of the
projection 13 shown in FIG. 1C and is incident on the skin of the person
to be measured. Luminous fluxes diffused in the skin as described later
are incident on the optical system provided in the casing 11 via the first
and second incident ports 15, 16. Further, a power switch 11a and a reset
switch 45 (see FIG. 3) are provided at a rear end of one side surface of
the casing 11 in FIG. 1A and on a back surface thereof, respectively.
FIG. 2 shows an optical system 20 accommodated in the casing 11. The
optical system 20 has the xenon tube 21 (light emitting means) as a light
source, and a light (white light) having a plurality of wavelengths is
produced when the xenon tube 21 is driven.
One end 23 of an optical fiber 22 which acts as a guiding means is opposed
to the xenon tube 21. The light from the xenon tube 21 is introduced to an
other end 24 of the optical fiber 22, and emerges out through the emerging
port 14 of the projection 13 (see FIG. 1) therefrom. The emergent luminous
fluxes are incident on the skin of the person to be measured, and those
diffused in the skin as described later are incident on one end 261 of an
optical fiber 251 via the first incident port 15 and on one end 262 of an
optical fiber 252 via the second incident port 16 from the outer surface
of the skin. In other words, the emerging port 14 coincides with the other
end 24 of the optical fiber 22, the first incident port 15 coincides with
the other end 261 of the optical fiber 251 and the second incident port 16
coincides with the one end 262 of the optical fiber 252.
The diffused luminous fluxes incident on the one end 261 of the optical
fiber 251 are introduced to the other end 271 and emerged therefrom,
whereas those incident on the one end 262 of the optical fiber 252 are
introduced to the other end 272 and emerge therefrom.
The luminous fluxes emerged from the other ends 271 (272) are incident on a
dichroic mirror 281 (282) for reflecting luminous fluxes in a blue
wavelength range, thereby splitting them in two directions.
The luminous fluxes 291 (292) reflected by the dichroic mirror 281 (282)
are gathered by a focusing lens 301 (302) and received by a photoelectric
conversion device 321 (322) such as a photodiode via a blue filter 311
(312). The luminous fluxes having transmitted through the dichroic mirror
281 (282) are gathered by a focusing lens 341 (342) and received by a
photoelectric conversion device 361 (362) such as a photodiode via a green
filter 351 (352).
The optical fiber 251 constructs a first light guiding means, and the
optical fiber 252 constructs a second light guiding means. Further, the
photoelectric conversion device 321 constructs a first photoelectric
conversion means; the photoelectric conversion device 361 constructs a
second photoelectric conversion means; the photoelectric conversion device
322 constructs a third photoelectric conversion means; and the
photoelectric conversion device 362 constructs a fourth photoelectric
conversion means. Furthermore, the dichroic mirror 281 constructs a first
splitting means, and the dichroic mirror 282 constructs a second splitting
means.
The optical fibers 23, 251, 252 are each formed by a bundle of a multitude
of fine fibers made of glass or synthetic resin.
By the optical system 20 constructed as above, the luminous fluxes in the
blue wavelength range (first wavelength range) are incident on the
photoelectric conversion devices 321, 322, and those in a green wavelength
range (second wavelength range) are incident on the photoelectric
conversion devices 361, 362. If light reception amounts of the
photoelectric conversion devices 321, 322 are I.sub.1 (.lambda.b), I.sub.2
(.lambda.b), and those of the photoelectric conversion device 361, 362 are
I.sub.1 (.lambda.kg), I.sub.2 (.lambda.g), the following relationships are
established:
I.sub.1 (.lambda.b)<I.sub.1 (.lambda.g),
I.sub.2 (.lambda.b)<I.sub.2 (.lambda.g)
since bilirubin pigmented in the subcutaneous fat has a larger absorption
coefficient (absorption factor) for luminous fluxes in the blue wavelength
range.
FIG. 3 is a block diagram showing an electric construction of the bilirubin
concentration measuring apparatus 10 shown in FIG. 1A. This measuring
apparatus 10 is provided with a controller 40 comprised of a CPU, etc., a
light source driving device 41 for driving the xenon tube 21, a
measurement switch 42 which is automatically turned on when the projection
13 (see FIG. 1) is pushed into the casing 11 against the biasing force of
the biasing means as described above, analog-to-digital (A/D) converters
431, 432, 441, 442, a reset switch 45 for clearing the measurement result
and bringing the apparatus into a state ready for a next measurement, a
ROM 46 for storing a control program for the controller 40 and fixed data
set in advance, and a RAM 47 for temporarily storing electric signal data.
The RAM 47 has a backup power supply (not shown) lest the content in the
memory should be erased. Instead of the RAM 47 having the backup power
supply, a reloadable nonvolatile memory such as an EEPROM may be used as a
storage means.
The controller 40 has a function as a light emission control means and is
electrically connected with the light source driving device 41. AS the
projection 13 is pushed to a specified position in the casing 11 against
the biasing force of the biasing means as described above, the measurement
switch 42 is automatically turned on and an emission command signal is
accordingly sent from the controller 40 to the light source driving device
41, which in turn drives the xenon tube 21.
The photoelectric conversion devices 321, 361 for receiving the luminous
fluxes 291, 331 having transmitted through the optical fiber 251 (see FIG.
2) and having been split by the dichroic mirror 281 are electrically
connected with the controller 40 via the A/D converters 431, 441,
respectively. Electric signals S.sub.1 (.lambda.b), S.sub.1 (.lambda.g)
proportional to the light reception amounts I.sub.1 (.lambda.b), I.sub.1
(.lambda.g) are outputted from the photoelectric conversion devices 321,
361 to the controller 40.
Likewise, the photoelectric conversion devices 322, 362 for receiving the
luminous fluxes 292, 332 having transmitted through the optical fiber 252
(see FIG. 2) and having been split by the dichroic mirror 282 are
electrically connected with the controller 40 via the A/D converters 432,
442, respectively. Electric signals S.sub.2 (.lambda.b), S.sub.2
(.lambda.g) proportional to the light reception amounts I.sub.2
(.lambda.b), I.sub.2 (.lambda.g) are outputted from the photoelectric
conversion devices 322, 362 to the controller 40.
The controller 40 also has a function as a concentration calculating means;
calculates a bilirubin concentration in accordan | | |
