Liver function testing apparatus
First Claim
1. A liver function testing apparatus for testing a liver function, comprising:
- light source means (11,
12) for exposing vital tissue (15) to a first light signal capable of being absorbed by a specific dye injected into the blood of said vital tissue, said dye to be taken in and removed by the liver, and to a second light signal capable of not being absorbed by said specific dye;
photoelectric conversion means (13) for outputting first and second photoelectric conversion signals based on light from said vital tissue and corresponding to said first light signal and to said second light signal applied to said vital tissue by said light source means;
sampling means (28) for sampling said photoelectric conversion outputs from said photoelectric conversion means;
decision means (34, PS28) for determining a coefficient of a regression line expression between said first and second photoelectric conversion signals on the basis of variable components in said vital tissue included in said first and second photoelectric conversion signals sampled by said sampling means;
arithmetic means (34, SP28) for processing a value correlated with a specific dye concentration in said blood on the basis of a sampling signal output from said sampling means during a prescribed period of time following said injection of said specific dye and said coefficient of said regression line expression determined by said decision means to obtain a coefficient of a simulation function as a function of time by using the method of least squares for processing said correlated value; and
wherein said arithmetic means comprise means for obtaining an index expressing the total amount of hepatic cell function on the basis of said coefficient of said simulation function obtained by said arithmetic means.
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Accused Products
Abstract
A liver function testing apparatus, provides light signals (11, 12) exposing vital tissue (15) to a first light signal that is substantially absorbed by a specific dye dosed into the blood of the vital tissue. The dye is to be taken in and removed by the liver. A second light signal is substantially not absorbed by the specific dye. Optical pulses obtained from the vital tissue are received by a light receiving element (13), the output of which is sampled by an A-D converter (30) to provide digital output signals. On the basis of variable components in the blood, a CPU (34) determines a coefficient of a regression line expression between first and second photoelectric conversion signals, to perform a biocalibration. A value correlated with a specific dye concentration in the blood, is processed on the basis of sampling signals during a prescribed period after an injection of the specific dye and the determined coefficient of the regression line expression, so that a coefficient of a simulation function is obtained as a function of time using the method of least squares. Additionally, an index RMAX expressing the total amount of hepatic cell function is obtained on the basis of the coefficients.
11 Citations
15 Claims
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1. A liver function testing apparatus for testing a liver function, comprising:
- light source means (11,
12) for exposing vital tissue (15) to a first light signal capable of being absorbed by a specific dye injected into the blood of said vital tissue, said dye to be taken in and removed by the liver, and to a second light signal capable of not being absorbed by said specific dye;
photoelectric conversion means (13) for outputting first and second photoelectric conversion signals based on light from said vital tissue and corresponding to said first light signal and to said second light signal applied to said vital tissue by said light source means;
sampling means (28) for sampling said photoelectric conversion outputs from said photoelectric conversion means;
decision means (34, PS28) for determining a coefficient of a regression line expression between said first and second photoelectric conversion signals on the basis of variable components in said vital tissue included in said first and second photoelectric conversion signals sampled by said sampling means;
arithmetic means (34, SP28) for processing a value correlated with a specific dye concentration in said blood on the basis of a sampling signal output from said sampling means during a prescribed period of time following said injection of said specific dye and said coefficient of said regression line expression determined by said decision means to obtain a coefficient of a simulation function as a function of time by using the method of least squares for processing said correlated value; and
wherein said arithmetic means comprise means for obtaining an index expressing the total amount of hepatic cell function on the basis of said coefficient of said simulation function obtained by said arithmetic means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
- light source means (11,
Specification