Realtime ultrasound diagnosis over a wide-area network (WAN) using off-the-shelf components

Inexpensive, realtime tele-ultrasound using a commercial, web-based video streaming device

We have devised an inexpensive, web-based tele-ultrasound system using commercially-available video streaming equipment. We examined the spatial and grey scale resolution, and the delay time of the system. The receiving PC was tested at various distances from the transmitting site, from 3.2 km to 4828 km. Standard resolution targets and echocardiography movie strips recorded on DVDs were used to assess the image quality. A qualitative assessment was made by an expert sonographer. As the distance between the transmitter and the receiver increased, the scan smoothness decreased and the delay increased. At a distance of 3.2 km the delay was 2–3 s, and at 4828 km it was 10–15 s. The delay was short enough to allow realtime guidance of the scanning technician by telephone. The system allows inexpensive, readily available, realtime tele-ultrasonography.

Review of technology: planning for the development of telesonography

Teleradiology allows contemporaneous interpretation of imaging exams performed at some distance from the interpreting radiologist. The transmitted images are usually static. However, there is benefit to real-time review of full-motion ultrasound (US) exams as they are performed. Telesonography is transmission of full-motion sonographic data to a remote site. We hypothesize that US exams, read after having been compressed utilizing Motion Picture Experts Group version 4 (MPEG-4) compression scheme, transmitted over the Internet as streaming multimedia, decompressed, and displayed, are equivalent in diagnostic accuracy to reading the examinations locally. MPEG-4 uses variable compression on each image frame to achieve a constant output bit rate. With less compression, the bit rate rises, and the only way the encoder can contain bit rate within the set bandwidth is by lowering frame rate or reducing image quality. We review the relevant technologies and industry standard components that will enable low-cost telesonography.

Real-time radiology--new concepts for teleradiology

We propose two new concepts for teleradiology: 'real-time radiology' and 'seamless operation of a workstation to view images from both local and remote hospitals'. In this paper, we describe an experimental real-time radiology system with a new multimedia diagnostic workstation, which has been established under teleradiology concepts and can be used for cooperative diagnosis by interchanging radiographic images bilaterally in real-time during an audio-visual discussion. The clinical evaluation of real-time radiology using a newly developed diagnostic workstation demonstrated the system to be practical and routinely available to enhance the radiological diagnostic quality of teleradiology.

Development and clinical application of a telemedicine support system in the field of perinatal patient management

In recent years, perinatal patient management has been greatly improved due to the advance of medical technologies in various fields. The primary objectives of perinatal patient management are to discover signs and symptoms of fetal asphyxia and threatened premature delivery at an early stage and to initiate treatment as soon as possible. For this purpose, continuous monitoring of the fetal heart rate and uterine contractions is most effective. We developed a telemedicine support system for pregnant women and evaluated it to see if that makes it possible 1) to manage pregnant women monitored at home in the same way as those who visit hospitals on an ambulatory basis, and 2) to prevent adverse events in women in a high-risk pregnancy. The findings obtained in the present study showed that this system is useful for both purposes. Perinatal telemedicine is expected to progress significantly in the next few years, although there are a number of issues that need to be resolved in this area.

A compression and transmission system of ultrasonic image sequence for telemedicine

OBJECTIVE

A newly developed compression and transmission system of ultrasound image sequence for telemedicine is proposed for transmitting ultrasonic image sequence in real time via IP-connected computers for telemedicine.

MATERIALS AND METHODS

In the compression method, the characteristics of ultrasound images were taken into account. Only sound data were essential, and the histogram of the images had two narrow distributions around black-and-white areas. The sound data, therefore, were run length encoded and then transmitted. In the transmission, UDP/IP was employed with a time weight insertion among the packets so as not to overflow the data buffers of computers in this system to derive the maximum transmission performance up to the network capacity. The decompression method was the same as the generation of the sector scan images from the sound data, so that natural ultrasound image sequence could be obtained.

RESULTS

This system was evaluated by transmitting the ultrasonic image sequence of the heart via ISDN (1. 5 mbps). Although this system completely specialized in compression and transmission of the ultrasound sector scan image sequence, a relatively good performance in the frame rate and the image quality was achieved, compared with the previous systems (H.260, JPEG, and MPEG-1).