Patent Publication Number: US-2010124790-A1

Title: Portable optical biosensor measuring apparatus and measurement method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This U.S. non-provisional patent application claims priority under 35 U.S.C. §119 of Korean Patent Application No. 10-2008-0114580, filed on Nov. 18, 2008, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     The present invention disclosed herein relates to an optical biosensor measuring apparatus, and more particularly, to a portable optical biosensor measuring apparatus. 
     The optical biosensor measuring apparatus is an apparatus that detects a specific antigen using optical characteristic of an optical biosensor. An antibody against a specific antigen is fixed in the optical biosensor sensor. Accordingly, when serum or other fluids including an antigen flows into the optical biosensor, the optical characteristic of the optical biosensor is varied with the combination of the antibody and the antigen. 
     Hereinafter, a process of obtaining the concentration of the antigen using the characteristics of the optical biosensor will be described in detail. First, transmittance spectrum, reflectance spectrum, or transmittance/reflectance spectrum in accordance with the wavelength before an antigen-antibody reaction are measured. The measurement results are compared to variations with the time lapse of the transmittance spectrum, the reflectance spectrum, or the transmittance/reflectance spectrum in accordance with wavelength after a specific antigen-antibody reaction of the optical biosensor. By using the comparison result, it is determined whether the specific antigen exists, and also the concentration of the specific antigen is measured. 
     SUMMARY OF THE INVENTION 
     The present invention provides a portable optical biosensor measuring apparatus. 
     The present invention also provides a portable optical biosensor measuring method. 
     Embodiments of the present invention provide portable optical biosensor measuring apparatuses including: a light emitting unit emitting a light having a first line width; an optical biosensor receiving an output light from the light emitting unit; and a peak wavelength detector detecting one peak wavelength having a second line width from a light from the optical biosensor, wherein the first line width may be greater than the second line width, and the optical biosensor may provide the peak wavelength according to an antigen-antibody reaction. 
     In some embodiments, the portable optical biosensor measuring apparatus may further include an optical filter disposed between the optical biosensor and the peak wavelength detector, the optical filter being a band pass filter transmitting the peak wavelength having the second line width in the light from the optical biosensor. 
     In other embodiments, the light from the optical biosensor may be a transmitted light through the optical biosensor. 
     In still other embodiments, the portable optical biosensor measuring apparatus may further include an optical splitter disposed between the light emitting unit and the optical biosensor; and an output light detecting unit measuring a power of the output light from the light emitting unit, wherein the optical splitter may split the light into the optical biosensor and the output light detecting unit, and the output light detecting unit may measure the power of the light split by the optical splitter. 
     In even other embodiments, the portable optical biosensor measuring apparatus may further include an optical split disposed between the light emitting unit and the optical biosensor, wherein the output light from the light emitting unit may be provided to the optical biosensor through the optical splitter, and the optical splitter may provide the light from the optical biosensor to the peak wavelength detector. 
     In yet other embodiments, the light from the optical biosensor may be a reflected light from the optical biosensor. 
     In further embodiments, a portable optical biosensor measuring apparatus may further include an optical filter disposed between the optical splitter and the peak wavelength detector, the optical filter being a band pass filter transmitting the peak wavelength having the second line width in the reflected light. 
     In still further embodiments, a portable optical biosensor measuring apparatus may further include an optical circulator disposed between the light emitting unit and the optical biosensor, wherein the output light from the optical emitting unit is provided to the optical biosensor through the optical circulator, and the optical circulator provides the light from the optical biosensor to the peak wavelength detector. 
     In even further embodiments, a portable optical biosensor measuring apparatus may further include an optical filter disposed between the optical circulator and the peak wavelength detector, the optical filter being a band pass filter transmitting the peak wavelength having the second line width in the light from the optical biosensor. 
     In yet further embodiments, the peak wavelength detector may include: a color filter reflecting a portion of an incident light and transmitting a portion of the incident light of the peak wavelength detector; a first color filter photodetector detecting a reflected light from the color filter; and a second color filter photodetector detecting a transmitted light through the color filter, wherein the transmission coefficient and reflection coefficient of the color filter continuously increase or decrease according to the wavelength of the light. 
     In yet further embodiments, a portable optical biosensor measuring apparatus may further include: a first color filter lens disposed between the first color filter photodetector and the color filter; and a second color filter lens disposed between the second color filter photodetector and the color filter, wherein the first and second color filter lenses converge the light on the first and second color filter photodetectors, respectively. 
     In yet further embodiments, a portable optical biosensor measuring apparatus may further include first and second log amplifiers and a subtracter, wherein the first log amplifier receives a first output signal from the first color filter photodetector to provide the first input signal to the subtracter, the second log amplifier receives a second output signal from the second color filter photodetector to provide the second input signal to the subtracter, and the subtracter outputs a difference between the first input signal and the second input signal. 
     In yet further embodiments, the peak wavelength detector may include: a wavelength division multiplex (WDM) coupler receiving an incident light to provide first and second WDM output lights; a first WDM photodetector detecting a light from the first WDM output light; and a second WDM photodetector detecting a light from the second WDM output light, wherein the first WDM output light from the WDM coupler increases according to the wavelength thereof, and the second WDM output light from the WDM coupler decreases according to the wavelength thereof. 
     In yet further embodiments, the peak wavelength detector may include: an optical splitter splitting the input light into first and second output lights; a thin film interference filter receiving the first output light to monotonically increase or decrease the transmittance at a predetermined band; a first interference photodetector detecting a transmitted light through the thin film interference filter; and a second interference photodetector detecting a light from the second output light. 
     In yet further embodiments, the peak wavelength detector may include: an optical diverger diverging an incident light; a Fabrit-Perot filter changing a path of an output light from the optical diverger according to whether the incident light is a vertical incident light or an inclined incident light; a first photodetector detecting a first output light of the vertical incident light through the Fabrit-Perot filter; and a second photodetector detecting a second output light of the inclined incident light through the Fabrit-Perot filter. 
     In yet further embodiments, the peak wavelength detector may include a photodiode, a current of the photodiode changed according to a reverse bias voltage. 
     In other embodiments of the present invention, measurement methods of a portable optical biosensor measuring apparatus include: outputting an output light having a first line width; providing the output light to an optical biosensor; and detecting one peak wavelength having a second line width from a light from the optical biosensor, wherein the first line width is greater than the second line width, and the optical biosensor provides the peak wavelength according to an antigen-antibody reaction. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The accompanying figures are included to provide a further understanding of the present invention, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present invention and, together with the description, serve to explain principles of the present invention. In the figures: 
         FIGS. 1   a  to  1   c  are diagrams illustrating concept and wavelength-power characteristic of an optical biosensor measuring apparatus according to an embodiment of the present invention; 
         FIG. 2  is a diagram illustrating an optical biosensor measuring apparatus according to another embodiment of the present invention; 
         FIGS. 3   a  to  3   d  are diagrams illustrating concept and wavelength-power characteristic of an optical biosensor measuring apparatus according to still another embodiment of the present invention; 
         FIGS. 4   a  to  4   d  are diagrams illustrating concept and wavelength-power characteristic of an optical biosensor measuring apparatus according to even another embodiment of the present invention; 
         FIGS. 5   a  to  5   d  are diagrams illustrating concept and wavelength-power characteristic of an optical biosensor measuring apparatus according to yet another embodiment of the present invention; 
         FIGS. 6   a  to  6   c  are diagrams illustrating concept and wavelength characteristic of a peak wavelength detector according to an embodiment of the present invention; 
         FIGS. 7   a  to  7   c  are diagrams illustrating concept and wavelength characteristic of a peak wavelength detector according to another embodiment of the present invention; 
         FIG. 8  is a diagram illustrating concept of a peak wavelength detector according to still another embodiment of the present invention; 
         FIGS. 9   a  and  9   b  are diagrams illustrating concept and wavelength characteristic with respect to incident angles of a peak wavelength detector according to even another embodiment of the present invention; and 
         FIG. 10  is a diagram illustrating a peak wavelength detector according to yet another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Preferred embodiments of the present invention will be described below in more detail with reference to the accompanying drawings. The present invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. 
     An optical biosensor measuring apparatus according to an embodiment of the present invention may directly measures peak wavelengths of a reflected light and a transmitted light. Thus, the optical biosensor measuring apparatus may be portable, and made at a low cost. 
     Hereinafter, preferred embodiments of the present invention, which can be carried out by those skilled in the art, will be described in detail with reference to the accompanying drawings. 
     While fully describing the operation principles of the preferred embodiment of the present invention, detailed descriptions related to well-known functions or configurations will be ruled out in order not to unnecessarily obscure the important aspects of the present invention. Like reference numerals refer to like elements throughout the drawings. 
       FIGS. 1   a  to  1   c  are diagrams illustrating concept and wavelength-power characteristic of an optical biosensor measuring apparatus according to an embodiment of the present invention. 
     Referring to  FIGS. 1   a  to  1   c,  the optical biosensor measuring apparatus include a light emitting unit  100  emitting a light having a first line width, an optical biosensor  110  directly or indirectly receiving the output light from the light emitting unit  100 , and a peak wavelength detector  120  detecting a peak wavelength having a second line width from a reflected light or a transmitted light of the optical biosensor  110 . The first line width is greater than the second line width. The optical biosensor  110  provides the peak wavelength in accordance with the antigen-antibody reaction. The line width means a full width half maximum (FWHM). 
     The light emitting unit  100  outputs the output light P 0  having a first line width Δλ s . The first line width Δλ s  and the center wavelength λ 3  thereof are variable. The power of the output light P 0  of the light emitting unit  100  may be controlled. The output light P 0  of the light emitting unit  100  may be directly provided to the optical biosensor  110 . The optical biosensor  110  may fix an antibody. The optical biosensor  110  may receive an antigen from blood, etc. A Light having one or more frequency bands in accordance with the antigen-antibody reaction of the blood may be transmitted through the optical biosensor  110 . 
     The transmitted light P 1  of the optical biosensor  110  may be provided to the peak wavelength detector  120 . The peak wavelength detector  120  may detect one peak wavelength λ p  having a second line width Δλ D . The peak wavelength detector  120  may detect the peak wavelength λ p  without a spectral apparatus (not shown). The spectral apparatus requires a broad space because using a diffraction grid. The peak wavelength λ p  detected by the peak wavelength detector  120  may depend on whether an antigen exists in blood and the like, or the concentration of the antigen. The concrete structure of the peak wavelength detector  120  will be described later. The peak wavelength detector  120  may include a microprocessor, which may detect the presence and concentration of an antigen using the peak wavelength. Also, the peak wavelength detector  120  may further include a display unit displaying the presence and the concentration of the antigen. 
     The wavelength of the light emitting unit  100  may include at least one of an infrared band, a visible band, and an ultraviolet band. The first line width Δλ s  of the emitted light from the light emitting unit  100  may be several times greater than the second line width of the incident light to the peak wavelength detector  120 . 
       FIG. 2  is a diagram illustrating an optical biosensor measuring apparatus according to another embodiment of the present invention. 
     Referring to  FIG. 2 , a light emitting unit  100  emits an output light P 0  having a first line width. The output light P 0  of the light emitting unit  100  is provided to an optical splitter  130 . The optical splitter  130  outputs first and second output light P 2  and P 3  by receiving the output light P 0 . The first output light P 2  of the optical splitter  130  may be provided to an optical biosensor  110 . A transmitted light P 1  through the optical biosensor  110  may be provided to a peak wavelength detector  120 . The peak wavelength detector  120  may output the presence and the concentration of an antigen in blood, by detecting a peak wavelength having a second line width. 
     The second output light P 3  of the optical splitter  130  may be provided to an output photodetector  132 . The output photodetector  132  may include at least one of a photodiode, a photo multiplier, a charge coupled device (CCD), and a CMOS image sensor (CIS). The output detector  132  may detect an output power of the light emitting unit  100 . When the output power of the light emitting unit  100  fluctuates, the light emitting unit  100  may be controlled so as to provide a constant power by detecting the fluctuation of the output power. 
       FIGS. 3   a  to  3   d  are diagrams illustrating concept and wavelength-power characteristic of an optical biosensor measuring apparatus according to still another embodiment of the present invention. 
     Referring to  FIGS. 3   a  to  3   d,  a light emitting unit  100  emits an output light P 0  having a first line width Δλ s . The output light P 0  of the light emitting unit  100  is provided to an optical splitter  130 . The optical splitter  130  outputs first and second output light P 4  and P 3  by receiving the output light P 0 . The first output light P 4  of the optical splitter  130  may be provided to an optical biosensor  110 . A transmitted light P 2  through the optical biosensor  110  may include a plurality of peak wavelengths (λ p1 , λ p2  and λ p3 ). The plurality of peak wavelengths (λ p1 , λ p2  and λ p3 ) may be formed in accordance with an antigen-antibody reaction. The transmitted light P 2  through the optical biosensor  110  may be provided to an optical filter  140 . The optical filter  140  may be a band pass filter through which only specific band one of the plurality of peak wavelengths (λ p1 , λ p2  and λ p3 ) can transmit. The optical filter  140  provides an output light P 1  having one peak wavelength λ p3  having a second line width Δλ D  to the peak wavelength detector  120 . The peak wavelength detector  120  may output the presence and the concentration of an antigen in blood, by detecting one peak wavelength λ D3  having the second line width Δλ D . 
     The second output light P 3  of the optical splitter  130  may be provided to an output photodetector  132 . The output photodetector  132  may include a photodiode. The output photodetector  132  may measure an output power from the light emitting unit  100 . When the output power of the light emitting unit  100  fluctuates, the light emitting unit  100  may be controlled so as to provide a constant power by detecting the fluctuation of the output power. 
       FIGS. 4   a  to  4   d  are diagrams illustrating concept and wavelength-power characteristic of an optical biosensor measuring apparatus according to even another embodiment of the present invention. 
     Referring to  FIGS. 4   a  to  4   d,  the optical biosensor measuring apparatus may include a light emitting unit  100  emitting a light having a first light width Δλ s , an optical biosensor  110  indirectly receiving the output light P 0  from the light emitting unit  100 , and a peak wavelength detector  120  detecting a peak wavelength λ p3  having a second line width Δλ D  from a reflected light of the optical biosensor  110 . The first line width Δλ s  is greater than the second line width Δλ D . The optical biosensor  110  provides the peak wavelength Δλ p3  in accordance with the antigen-antibody reaction. 
     The light emitting unit  100  outputs the output light P 0  having a first line width Δλ s . The first line width Δλ s  and the center wavelength λ 3  thereof are variable. The power of the output light P 0  of the light emitting unit  100  may be controlled. The output light P 0  of the light emitting unit  100  may be provided to the optical splitter  130 . The optical splitter  130  outputs first and second output light P 1  and P 5  by receiving the output light P 0 . The first output light P 1  may be directly provided to an optical biosensor  110 . The optical biosensor  110  may fix an antibody. The optical biosensor  110  may receive an antigen from blood, etc. The optical biosensor  110  may reflect one or more bands in accordance with an antigen-antibody reaction of the blood. A reflected light P 2  from the optical biosensor  110  may include a plurality of peak wavelengths (λ p1 , λ p2  and λ p3 ). The plurality of peak wavelengths (λ p1 , λ p2  and λ p3 ) may be formed in accordance with the antigen-antibody reaction. The reflected light P 2  from the optical biosensor  110  may be provided to the optical splitter  130 , so that the optical path thereof may be changed. The reflected light P 4  with the changed optical path may be provided to an optical filter  140 . The optical filter  140  may be a band pass filter through which only specific band one of the plurality of peak wavelengths (λ p1 , λ p2  and λ p3 ) can transmit. The optical filter  140  may provide an output light P 3  having one peak wavelength λ p3  having a second line width Δλ D  to the peak wavelength detector  120 . The peak wavelength detector  120  may output the presence and the concentration of an antigen in blood, by detecting one peak wavelength λ p3  having the second line width Δλ D . 
     The second output light P 5  of the optical splitter  130  may be provided to an output photodetector  132 . The output photodetector  132  may include a photodiode. The output photodetector  132  may measure an output power from the light emitting unit  100 . When the output power of the light emitting unit  100  fluctuates, the light emitting unit  100  may be controlled so as to provide a constant power by detecting the fluctuation of the output power. 
       FIGS. 5   a  to  5   d  are diagrams illustrating concept and wavelength-power characteristic of an optical biosensor measuring apparatus according to yet another embodiment of the present invention. 
     Referring to  FIGS. 5   a  to  5   d,  the optical biosensor measuring apparatus may include a light emitting unit  100  emitting a light having a first light width Δλ s , an optical biosensor  110  indirectly receiving the output light P 0  from the light emitting unit  100 , and a peak wavelength detector  120  detecting a peak wavelength λ p3  having a second line width Δλ D  from a reflected light P 2  of the optical biosensor  110 . The first line width Δλ s  is greater than the second line width Δλ D . The optical biosensor  110  provides the peak wavelength Δλ p3  in accordance with the antigen-antibody reaction. 
     The light emitting unit  100  outputs the output light P 0  having a first line width Δλ s . The first line width Δλ s  and the center wavelength λ 3  thereof are variable. The power of the output light P 0  of the light emitting unit  100  may be controlled. The output light P 0  of the light emitting unit  100  may be provided to an input terminal N 1  of an optical circulator  170 . The optical circulator  170  may be a three terminal optical device. The optical circulator  170  outputs a first output light P 1  to a first output terminal N 2  by receiving the output light P 0  from the light emitting unit  100  at the input terminal N 1 . The first output light P 1  may re-enter the first output terminal N 2  by reflection from the optical biosensor  110 . The incident light P 2  to the first output terminal N 2  may outputted in a form of a second output light via a second output terminal N 3 . 
     The first output light P 1  of optical circulator  170  may be directly provided to an optical biosensor  110 . The optical biosensor  110  may fix an antibody. The optical biosensor  110  may receive an antigen from blood, etc. The optical biosensor  110  may reflect one or more bands in accordance with an antigen-antibody reaction of the blood. A reflected light P 2  from the optical biosensor  110  may include a plurality of peak wavelengths (λ p1 , λ p2  and λ p3 ). The plurality of peak wavelengths (λ p1 , λ p2  and λ p3 ) may be formed in accordance with the antigen-antibody reaction. The reflected light P 2  from the optical biosensor  110  may be again inputted into the first output terminal N 2  of the optical circulator  170  to output the second output light P 4  through the second output terminal N 3 . The second output light P 4  may be provided to an optical filter  140 . The optical filter  140  may be a band pass filter through which only specific band one of the plurality of peak wavelengths (λ p1 , λ p2  and λ p3 ) can transmit. The optical filter  140  may provide an output light P 3  having one peak wavelength λ p3  having a second line width Δλ D  to the peak wavelength detector  120 . The peak wavelength detector  120  may output the presence and the concentration of the antigen in blood, by detecting one peak wavelength λ p3  having the second line width Δλ D . 
       FIGS. 6   a  to  6   c  are diagrams illustrating concept and wavelength characteristic of a peak wavelength detector according to an embodiment of the present invention. 
     Referring to  FIGS. 6   a  to  6   c,  the peak wavelength detector  120  may include a color filter  121  reflecting a portion of an incident light I 0  and transmitting a portion of the incident light I 0 , a first color filter photodetector  123  detecting a reflected light I 1  from the color filter  121 , and a second color filter photodetector  122  detecting a transmitted light I 2  through the color filter  121 . The transmittance T and reflectance R of the color filter  121  may continuously increase or decrease in accordance with the wavelength. The ratio T/R of the transmittance T to the reflectance R of the color filter  121  may increase in accordance with the wavelength. The ratio T/R of the transmittance T to the reflectance R of the color filter  121  may be in a one-to-one relationship with the wavelength. Accordingly, the transmittance T, the reflectance R, or the ratio T/R of the transmittance T to the reflectance R of the color filter  121  may determine the wavelength of the incident light I 0 . The incident light I 0  may include one peak wavelength having a second line width Δλ D . The first and second color filter photodetectors  123  and  122  may include at least one of a photodiode, a photo multiplier, a CCD, and a CIS. 
     A first color filter lens  124  may be disposed between the first color filter photodetector  123  and the color filter  121  to converge the reflected light I 1  on the first color filter photodetector  123 . The second color filter lens  125  may be disposed between the second color filter photodetector  122  and the color filter  121  to converge the transmitted light I 2  on the second color filter photodetector  122 . 
       FIGS. 7   a  to  7   c  are diagrams illustrating concept and wavelength characteristic of a peak wavelength detector according to another embodiment of the present invention. 
     Referring to  7   a  to  7   c,  the peak wavelength detector  120  may include a WDM (wavelength division multiplex) coupler  221 , a first WDM photodetector  222 , and a second WDM photodetector  223 . The WDM coupler  221  may provide first and second WDM output lights I 1  and I 2  by receiving an incident light I 0 . The first WDM photodetector  222  may detect a light from the first WDM output light I 1 , and the second WDM photodetector  223  may detect a light from the second WDM output light I 2 . The first WDM output light I 1  of the WDM coupler  221  may increase in accordance with the wavelength, and the second WDM output light I 2  of the WDM coupler  221  may decrease in accordance with the wavelength. 
     The WDM coupler  221  may be a three terminal device. The WDM coupler may include an input terminal N 1 , a first output terminal N 2 , and a second output terminal N 3 . The incident light I 0  may be inputted into the input terminal N 1  of the WDM coupler  221 . The ratio I 1 /I 2  of the transmittance I 1 /I 0  of the first output terminal N 2  to the transmittance I 2 /I 0  of the second output terminal N 3  may be increased in accordance with the wavelength. 
     The operation principle of the WDM coupler  221  is similar to that of the color filter as described above. The incident light I 0  may include one peak wavelength having a second line width Δλ D . Accordingly, the ratio I 1 /I 2  of the transmittance I 1 /I 0  of the first output terminal N 2  to the transmittance I 2 /I 0  of the second output terminal N 3  may determine the peak wavelength of the incident light I 0 . 
     The first WDM photodetector  222  or the second WDM photodetector  223  may include at least one of at least one of a photodiode, a photo multiplier, a CCD, and a CIS. 
       FIG. 8  is a diagram illustrating concept of a peak wavelength detector according to still another embodiment of the present invention. 
     Referring to  FIG. 8 , the peak wavelength detector may include an optical splitter  321 , a thin film interference filter  324 , a first interference photodetector  322 , and a second interference photodetector  323 . The optical splitter  321  may split an input light I 0  into first and second output light I 3  and I 1 . The thin film interference filter  324  may receive the first output light I 3  to monotonically increase or decrease the transmittance at a predetermined band. The first interference photodetector  322  may detect a transmitted light I 2  through the thin film interference filter  324 . The second interference photodetector  323  may detect the second output light I 1 . 
     The thin film interference filter  324  may perform a function similar to that of the color filter as described in  FIG. 6 . The incident light I 0  may include one peak wavelength having a second line width Δλ D . Accordingly, the ratio of the transmitted light to the reflected light of the thin film interference filter  324  may determine the peak wavelength of the incident light I 0 . The first or second interference photodetector  322  or  323  may include at least one of a photodiode, a photo multiplier, a CCD, and a CIS. 
       FIGS. 9   a  and  9   b  are diagrams illustrating concept and wavelength characteristic with respect to incident angles of a peak wavelength detector according to even another embodiment of the present invention. 
     Referring to  FIGS. 9   a  and  9   b,  the peak wavelength detector  120  may include an optical diverger  421 , a Fabrit-Perot filter  424 , a first photodetector  422 , and a second photodetector  423 . The optical diverger  421  may diverge an input light I 0 . The Fabrit-Perot filter  424  may change an optical path of the diverged light from the optical diverger  421  in accordance with an incident angle. The first photodetector  422  may detect a first output light I 1  of a vertical incident light I nor  toward the Fabrit-Perot filter  424 . The second photodetector  423  may detect a second output light I 2  of an inclined incident light I obl  toward the Fabrit-Perot filter  424 . 
     The inclined incident light I obl  may be inclined at a predetermined angle θ with respect to the vertical incident light I nor  in the Fabrit-Perot filter  424 . The wavelength having the maximum transmittance for the Fabrit-Perot filter  424  may depend on the refractive index of the Fabrit-Perot filter  424  and the predetermined angle θ. Accordingly, when the wavelength is identical, the transmittances of the inclined incident light I obl  and the vertical incident light I nor  through the Fabrit-Perot filter  424  may be different from each other. The ratio of the second output light I 2  of the inclined incident light I obl  to the first output light I 1  of the vertical incident light I nor  may be in a one-to-one relationship with the wavelength. The incident light I 0  may include one peak wavelength having a second line width Δλ D . Accordingly, if the ratio B/A of the transmittance of the inclined incident light I obl  to the transmittance of the vertical incident light I nor  is measured, the wavelength of the incident light I 0  may be known. 
     The first or second photodetector  422  or  423  may include at least one of a photodiode, a photo multiplier, a CCD, and a CIS. 
       FIG. 10  is a diagram illustrating a peak wavelength detector according to yet another embodiment of the present invention. 
     Referring to  FIG. 10 , the peak wavelength detector  120  may include a color filter  521  reflecting a portion of an incident light I 0  and transmitting a portion of the incident light I 0 , a first color filter photodetector  522  detecting a reflected light I 1  from the color filter  521 , and a second color filter photodetector  523  detecting a transmitted light I 2  through the color filter  521 . The transmittance T and reflectance R of the color filter  521  may continuously increase or decrease in accordance with the wavelength. The ratio T/R of the transmittance T to the reflectance R of the color filter  521  may increase in accordance with the wavelength. The ratio T/R of the transmittance T to the reflectance R of the color filter  521  may be in a one-to-one relationship with the wavelength. Accordingly, the transmittance T, the reflectance R, or the ratio T/R of the transmittance T to the reflectance R of the color filter  521  may determine the wavelength of the incident light I 0 . 
     The first and second color filter photodetectors  522  and  523  may include one of a photodiode, a photo multiplier, a CCD, and a CIS. Electrical output signals S 1  and S 2  of the first and the second color filter photodetectors  522  and  523  may be connected to first and second log amplifiers  524  and  525 . The first and second log amplifiers  524  and  525  may output log values corresponding to input values as output signals  01  and  02 . The output signals  01  and  02  of the first and second log amplifiers  524  and  525  may be inputted into a subtracter  526 . The subtracter  526  may output a difference between the output signals  01  and  02  of the first and second log amplifier  524  and  525 . The subtracter  526  may include an operational (OP) amplifier. 
     According to a modified embodiment of the present invention, the peak wavelength detector may include a photodiode. A current of the photodiode may vary with a reverse bias voltage. The current of the photodiode may depend on the wavelength. Accordingly, when the current of the photodiode according to the reverse bias is measured, the wavelength of the incident light to the photodiode may be known. 
     A portable optical biosensor measurement apparatus according to an embodiment of the present invention uses a light source with a broad wavelength band without using a variable wavelength, and detects a peak wavelength of a light in an optical biosensor. Accordingly, it is possible to exactly measure the concentration of an antigen in the antigen-antibody reaction of the optical biosensor. 
     The above-disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments, which fall within the true spirit and scope of the present invention. Thus, to the maximum extent allowed by law, the scope of the present invention is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description.