Video quality of 3G videophones for telephone cardiopulmonary resuscitation

摘要

We simulated a cardiopulmonary resuscitation (CPR) scene with a manikin and used two 3G videophones on the caller's side to transmit video to a laptop PC. Five observers (two doctors with experience in emergency medicine and three paramedics) evaluated the video. They judged whether the manikin was breathing and whether they would give advice for CPR; they also graded the confidence of their decision-making. Breathing was only visible from certain orientations of the videophones, at distances below 150 cm with good illumination and a still background. Since the phones produced a degradation in colours and shadows, detection of breathing mainly depended on moving contours. Low camera positioning produced better results than having the camera high up. Darkness, shaking of the camera and a moving background made detection of breathing almost impossible. The video from the two 3G videophones that were tested was of sufficient quality for telephone CPR provided that camera orientation, distance, illumination and background were carefully chosen. Thus it seems possible to use 3G videophones for emergency calls involving CPR. However, further studies on the required video quality in different scenarios are necessary.