Biological-information obtaining apparatus and method thereof

A biological-information obtaining apparatus comprising:

• light-emitting means for emitting white light;
• image-capturing means for capturing images, in time sequence, obtained by irradiating a living body with the light emitted and by causing the light to be transmitted through or reflected by the living body, the image-capturing means being sensitive to at least red and blue color components;
• extreme generation means for generating a maximum value and a minimum value, in time sequence, of each of the color components for certain regions of the captured images;
• and
• oxygen-saturation calculation means for calculating, on the basis of the maximum value and the minimum value of each of the color components, oxygen saturation by solving an equation of {(Rc−Bc)−(Re−Be)}/{Bc−Be)=[(Re−Be)×{S×Eo(λ1)+(1−S)×Er(λ1)}]/[Be×{S×Eo(λ2)+(1−S)×Er(λ2)}], where Rc represents the maximum value of the red component, Bc represents the maximum value of the blue component, Re represents the minimum value of the red component, Be represents the minimum value of the blue component, S represents oxygen saturation, Eo(λ) represents a known absorbance coefficient of oxyhemoglobin at a wavelength λ, Er(λ) represents a known absorbance coefficient of deoxyhemoglobin at a wavelength λ, and λ1 and λ2 represent specific values of wavelength λ.

A biological-information obtaining apparatus comprising:

• a light-emitting unit configured to emit light;
• an image-capturing unit configured to capture images, in time sequence, obtained by irradiating a living body with the light emitted and by causing the light to be transmitted through or reflected by the living body, the image-capturing unit being sensitive to at least two color components;
• an extreme generation unit configure to generate a maximum value and a minimum value, in time sequence, of each of the color components for certain regions of the captured images;
• and
• an oxygen-saturation calculation unit configured to calculate oxygen saturation on the basis of the maximum value and the minimum value of each of the color components.

A biological-information obtaining apparatus comprising:

• a light-emitting unit configured to emit white light;
• an image-capturing unit configured to capture images, in time sequence, obtained by irradiating a living body with the light emitted and by causing the light to be transmitted through or reflected by the living body, the image-capturing unit being sensitive to at least red and blue color components;
• an extreme generation unit configured to generate a maximum value and a minimum value, in time sequence, of each of the color components for certain regions of the captured images;
• and
• an oxygen-saturation calculation unit configured to calculate, on the basis of the maximum and the minimum of each of the color components, oxygen saturation by solving an equation of {(Rc−Bc)−(Re−Be)}/{Bc−Be}=[(Re−Be)×{S×Eo(λ1)+(1−S)×Er(λ1)}]/[Be×{S×Eo(λ2)+(1−S)×Er(λ2)}], where Rc represents the maximum value of the red component, Bc represents the maximum value of the blue component, Re represents the minimum value of the red component, Be represents the minimum value of the blue component, S represents oxygen saturation, Eo(λ) represents a known absorbance coefficient of oxyhemoglobin at a wavelength λ, Er(λ) represents a known absorbance coefficient of deoxyhemoglobin at a wavelength λ, and λ1 and λ2 represent specific values of wavelength λ.