Abstract: A method is provided for sampling and measuring the content of a low-molecular weight compound, such as glucose, cholesterol, or urea, in a complex fluid medium to be sampled, such as blood. A dialyzer is placed in contact with the complex fluid medium so that it passes through the dialyzer. One or more semipermeable membranes are disposed within the complex fluid medium to form one or more passageways for the passage of dialysis fluid, with the passageways being substantially smaller in volume than the volume of the surrounding complex fluid medium. A fractional portion of the complex fluid medium is acted on by the dialysis fluid and dialyzed so that only a fractional portion of the low-molecular weight compound diffuses into the passageways containing the dialysis fluid to produce a dialysate in the passageways. The dialysate is then measured to determine the content of the low-molecular weight compound in the complex fluid medium.

Abstract: A method and apparatus is provided for measuring the content of a compound in a liquid medium, and which is particularly useful for measuring the concentration of a low molecular weight compound in a complex medium in which there is provided a dialyzer in contact with the complex fluid medium and through which dialysis fluid is conducted to receive by diffusion a portion of the low molecular weight compound to produce a dialysate. The dialysate with the low molecular weight commpound to be examined is first conducted through a venting device for removal of gaseous particles therefrom before conduction through a reaction chamber containing enzymes for promoting the conversion of the low molecular weight compound in the dialysate into a converted reaction product.

Abstract: A method and apparatus is provided which measures the content of a low-molecular compound, such as glucose, cholesterol, or urea, in a complex medium, such as blood. A dialyzer is placed in contact with the complex medium so that the complex medium may pass therethrough. In addition, dialysis fluid is supplied through the dialyzer to produce a dialysate having a property which can be measured. In the preferred embodiment, an enzyme is added to the dialysate to chemically react with the low-molecular compound to produce a chemical change which can be measured.

Abstract: A method and apparatus is provided for measuring the content of a low-molecular weight compound in a complex medium which includes a dialyzer, conduits for conveying the complex medium through the dialyzer and conduits for supplying dialysis fluid to the dialyzer to receive by diffusion a portion of the low-molecular weight compound in the complex medium to produce a dialysate. Apparatus is also provided for conducting the dialysate produced from the dialyzer to a measuring unit, wherein the conducting apparatus includes a main flow line having an enzyme bed and a shunt flow line. A control device is provided for directing the flow of dialysate through the main flow line and the enzyme bed or the shunt flow line, so that the flow of dialysate bypasses the enzyme bed. Apparatus is also provided for comparing the dialysates in the main and shunt flow lines.