An instrument for liver function testing using an optical sensor

As a medical application of optoelectronic technology, an instrument to measure liver function was developed. For the estimation of liver function, Indocyanine green (ICG) is widely used as a tracer clinically. A description of an instrument for noninvasive measurement of ICG clearance and the results of the clinical evaluation of about 470 patients are presented. In in vivo measurement, to solve the problem of changing blood volume, the authors propose a novel calibration method before ICG injection. Using this instrument, called an ICG clearance meter, the value of ICG tests correlated well with the values calculated from the conventional blood sampling methods