Shizuoka University

Hamamatsu University School of Medicine

Masatsugu Niwayama

Naohiro Kanayama

Kazunao Suzuki

In a measurement target model representing a measurement target, this measurement sensitivity calculation device uses, as measurement sensitivity, an optical path length difference between a first optical path length indicating the length of an optical path through which light emitted from a light emitter to the measurement target travels before being received by a first light receiver spaced apart by a first distance from the light emitter and a second optical path length indicating the length of an optical path through which light emitted from the light emitter travels before being received by a second light receiver spaced apart by a second distance from the light emitter, calculates the measurement sensitivity for each depth of the measurement target, and outputs the measurement sensitivity calculated for each depth of the measurement target.

Measurement sensitivity calculation method, measurement sensitivity calculation device, recording medium storing measurement sensitivity calculation program, and optical measurement device

An accurate measurement can be made of the light absorbance of deep layer tissue such as in a human body or a fruit. The thickness of fat is computed. A first specific distance and a second specific distance corresponding to the computed fat thickness are computed based a predetermined relationship between the fat thickness, the first specific distance, and measurement sensitivity of a surface layer and measurement sensitivity of a deep layer when light is received at a position the first specific distance away from a light emitting means. A third specific distance and a fourth specific distance are computed corresponding to the computed fat thickness based on a predetermined relationship between the fat thickness, the third specific distance and a measurement sensitivity of an intervening layer and a measurement sensitivity of the deep layer when light is received at a position the third specific distance away from the light emitting means.

Optical measuring device

The present invention provides an optical measuring apparatus and an optical measuring method for being able to correct the influence of a superficial tissue to be able to accurately measure a degree of light absorption of a deep layer tissue such as a human body and fruits, and a storage medium that stores an optical measuring program. The optical measuring apparatus includes a probe, and the probe includes one light emitting diode and two photodiodes. In a configuration of the optical measuring apparatus, one of the photodiodes receives light which is emitted from the light emitting diode and transmitted through a superficial layer and a deep layer of a tissue, and the other photodiode receives light having a deep layer transmission distance different from that of the light received by one of the photodiodes. The light received by the other photodiode is also transmitted through the superficial layer and deep layer of the tissue. Based on intensity of the light received by each photodiode, a control unit computes a propagation constant in a medium through which the light propagates. An arithmetic expression is selected in accordance with an input fat thickness of the tissue, and an absorption coefficient of the light from a muscle tissue using the arithmetic expression based on the fat thickness and a spatial slope. A hemoglobin concentration and an oxygen saturation are obtained based on the obtained absorption coefficient of the light.

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Hamamatsu, Japan

Masatsugu Niwayama