Visual tests for measuring the picture quality of teleconsultations for medical purposes

Telemedicine provides a new way of delivering medical services. The good quality of the picture is, however, essential for a proper and reliable teleconsultation, especially in the cases when visual information about the patient's physical condition is of great importance as in ophthalmology and dermatology. Therefore real-time telemedical applications need standards for these procedures, e.g. minimum requirements for resolution, as well as contrast and color discrimination. The present study was carried out to test these parameters in a real environment. A panel of different resolution, contrast sensitivity and color discrimination tests was carried out for five test persons via PictureTel videoconference system by ISDN 128 kbit/s line speed and in a normal way. The good color discrimination of the teleconsultation system makes it possible to use the system in the evaluation of different skin lesions and exemas. However, the poor resolution and especially poor contrast sensitivity makes the use of the equipment valueless in the evaluation of diseases where the diagnoses are based on the discrimination of small details, like the biomicroscopical analysis of inflammatory cells in the aqua's humor in cases of intraocular inflammation. The authors are suggesting a simple panel of tests to optimize and standardize these parameters.