The determination of the oxygenation of blood in vitro by using reflected light
article
A method published by Brinkman and Zijlstra is referred to, by which it is possible to determine the degree of oxygenation of blood samples in vitro. By this method the fact is used, that the color of the light reflected by the blood depends on the percentage oxygen saturation. The advantages of this method are mentioned. It was found desirable to investigate the theoretical basis.
One after another the following points are dealt with:
1. A. A short description is given of the “Brinkman haemoreflector” and the way it is used.
2. B. The reflection theory of Schuster, as it has been extended by Dreosti, is discussed so far as necessary for the purpose proposed.
3. C. The theory is applied to the “haemoreflector”. An approximation formula (Equation 4) is derived and confirmed experimentally with a modified “haemoreflector”.
4. D. The instruction for the use of the “Brinkman haemoreflector” is not in accordance with the theory discussed earlier. There is a good agreement, however, when compared with the method of Van Slyke. An explanation of this phenomenon is given. It is evident, that there is a range of the percentage oxygen saturation scale (from x to 100 per cent saturation, where x is dependent on the quality of the photo-electric cell and the resistance on which the cell is connected), where the apparatus gives reliable values. In practice, x is found to vary from 40 to 55 per cent.
5. E. The method which uses a modified “haemoreflector” and which is in accordance with the theory is described briefly. It allows a correct determination throughout the whole range from 0 to 100 per cent saturation of the blood.
6. F. The results of comparative measurements between the “haemoreflector” and the method according to Van Slyke are discussed. The agreement proves to answer the expectations, as these may be formed on account of four considerations, which are worked out in some detail.
The standard deviation of the reflection method, as it follows from duplicate readings, is 1 per cent difference in oxygen saturation.
One after another the following points are dealt with:
1. A. A short description is given of the “Brinkman haemoreflector” and the way it is used.
2. B. The reflection theory of Schuster, as it has been extended by Dreosti, is discussed so far as necessary for the purpose proposed.
3. C. The theory is applied to the “haemoreflector”. An approximation formula (Equation 4) is derived and confirmed experimentally with a modified “haemoreflector”.
4. D. The instruction for the use of the “Brinkman haemoreflector” is not in accordance with the theory discussed earlier. There is a good agreement, however, when compared with the method of Van Slyke. An explanation of this phenomenon is given. It is evident, that there is a range of the percentage oxygen saturation scale (from x to 100 per cent saturation, where x is dependent on the quality of the photo-electric cell and the resistance on which the cell is connected), where the apparatus gives reliable values. In practice, x is found to vary from 40 to 55 per cent.
5. E. The method which uses a modified “haemoreflector” and which is in accordance with the theory is described briefly. It allows a correct determination throughout the whole range from 0 to 100 per cent saturation of the blood.
6. F. The results of comparative measurements between the “haemoreflector” and the method according to Van Slyke are discussed. The agreement proves to answer the expectations, as these may be formed on account of four considerations, which are worked out in some detail.
The standard deviation of the reflection method, as it follows from duplicate readings, is 1 per cent difference in oxygen saturation.
TNO Identifier
1007183
Source
American Heart Journal, 45(6), pp. 809-822.
Pages
809-822
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