| Zugriffsnummer | 17661 |
| Dokumenttyp | Zeitschriftenartikel |
| Sprache | Englisch |
| Titel | Evaluating clinical comparisons for human eye tonometers : a critical assessment of common practice |
| Autor(in); Institution |
Elster, Clemens; 8.4, Mathematische Modellierung und Datenanalyse, PTB-Berlin
Schwenteck, Thomas; 8.1, Medizinische Messtechnik, PTB-Berlin
Tilgner, E. J.; PTB-Berlin, retired staff
Draeger, J.; Universitäts-Augenklinik Hamburg, GERMANY
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| Quelle/Jahr | New Trends in Ophthalmology: XII (1997), 4, 91 - 96 |
| ISSN | 0394-3755 |
| Verlag | Roma: Libbey |
| Freie Schlagworte | Tonometer ; pressure assessment ; clinical comparisation measurements ; calibration ; least squares ; total least squares ; uncertainty |
| Zusammenfassung | Only accurate measurements of the intraocular pressure by means of human eye tonometers permit a correct diagnose of glaucomas. There are various tonometers in the medical application for these important measurements. For correct measurements of the intraocular pressure a calibration of nearly all tonometers by clinical comparison measurement must be carried out. The purpose for calibrating a tonometer contains not only the determination of the functional relation between the tonometer to be calibrated and a reference device but also often an adjustment of this tonometer. This adjustment is ingeniously if the total error is small in relation to the measured values and leads to the correction of the systematic error of the tonometer to be calibrated. For correct measurements of the intraocular pressure and for the application of the tonometer to be calibrated as transfer normal the calibration process must be performed in a corresponding quality. Therefore suitable error bounds are necessary. Simulations under realistic conditions show the previous error requirements being not appropriate for the description of the phenomenon of errors and lead to their replacement by new ones. These new requirements take into consideration statistical aspects of clinical comparison. A correct assessment of clinical comparison of the tonometer to be calibrated is possible. Besides a valuation of a difference method is represented, an often used calculation method in the medicine, at the performance of the tonometer certification in contrast to the total least-square method. |
