| 摘要 |
<p>The concentration of a substance, especially glucose, in the blood is measured in vivo by applying to the skin two wavelengths of infrared light and measuring the difference in the absorption of the two wavelengths, preferably in the range of 3-10 νm, one being a sample wavelength at which the substance shows a specific absorption and the other being a reference wavelength at which the substance shows no specific absorption. Simultaneously the concentrations of interfering components are measured in the same way and the result for the substance is corrected with regard to the measured concentrations of interfering components. Infrared light is transmitted through optical fibres (10, 10a) to a detector having two chambers (15, 15a), a sample wavelength to one chamber (15) and a reference wavelength to the other (15a), and a transducer (14) between the chambers measures the difference in the pressures induced in the respective chambers when the tissue beneath the chambers is heated by absorption of the infrared light transmitted to it.</p> |
