1. Field of the Invention
The present invention relates to an apparatus for measuring the activity of chemically special ions in humor or body fluid.
2. Description of the Prior Art
It is known that, among others, sodium (Na) and potassium (K) ions in body fluids play a physiologically important role. That is, Na and K ions occupy about 90% of a cation in serum and they are the most important components for osmotic pressure and acid radical and base equilibrium of the serum. Further, measurement of ions in the serum for representing cellular body fluid is important because conditions such as the water content, electrolytic metabolism and excitability of nerves, muscles, etc. can be diagnosed. Further, increase and decrease of the ion concentration plays a major role for diagnosing clinical diseases, such as diarrhea, hyperhydration, functional disorder of the heart, emesis and the like.
From the reasons explained in the foregoing measurement of various kinds of ions in a body fluid is carried out, but the most important is the measurement of Na ions and K ions. The latter may be measured a flame method or an atomic absorbing method. These methods, however, have many problems involving preparation before measurement, operationability and setting conditions. Moreover, these measuring methods derive the ion quantity in a sample instead of the activity of ions in a sample. Hence these methods are insufficient for the above-described purpose.