Technical evaluation of a low-bandwidth, Internet-based system for teleconsultations

A low-bandwidth telemedicine system was evaluated in eight community hospit als connected to a central hospital via the Internet. PCs were used with vi deoconferencing software and modem connections to the telephone network. Th e average data connection rates, still-image transfer times and live-video transmission rates were determined. The time to send 640 x 480, 320 x 240 a nd 160 x 120 pixel, 24-bit still images ranged from 29 s to 411 s. The aver age file transfer times for a 10 s MPEG video-clip was 8.6 min. The average live video frame rate was 1 frame/s (at the best image quality), with an a verage latency of 3 s. The results suggest that Internet-based videoconfere ncing is acceptable for certain telemedicine applications.