Real-time transmission of pediatric echocardiograms using a single ISDN line

Near real-time echocardiography teleconsultation using low bandwidth and MPEG-4 compression: feasibility, image adequacy and clinical implications

We assessed the feasibility, image adequacy and clinical utility of a tele-echocardiography service which combined video compression with low-bandwidth store-and-forward transmission. Echocardiograms were acquired by a hospital geriatrician, compressed and transmitted using both near real-time (urgent) and delayed (pre-programmed) protocols via an Internet connection to the notebook PC of a remote cardiologist. Clinical utility was evaluated as a change in therapeutic management. During a one-year period, 101 tele-echocardiography consultations were successfully performed (feasibility = 100%) on 95 patients (age 22-95 years), admitted with cardiovascular or neurological diagnoses (24% of the consultations were urgent). In total, 4617 files (1.4 GByte of data) were transmitted, 2669 of which were short video clips. On average, 46 files (13.8 MByte) were transmitted (mean duration 10 min) at each examination. Consultations (both urgent and pre-programmed) were clinically useful in 83% of examinations. Logistic regression analysis showed that both a low left ventricular systolic function and the examination indication were determinants of clinical utility. The transmitted images were considered adequate for diagnosis in 100% of the pre-programmed teleconsultations. Tele-echocardiography using MPEG-4 video compression is a feasible, adequate and clinically useful tool for telemedicine.

A novel indexing architecture for the provision of smart playback functions in collaborative telemedicine applications

This paper presents a novel indexing architecture to support a range of smart playback functions in collaborative telemedicine systems. These functions include replaying the session from a specified point in time, replaying all the session segments controlled by a particular physician, replaying all the session segments relating to a specific medical image, and playing a montage of the entire session. Since the contents of telemedicine sessions vary over time depending on the particular commands invoked by the physician(s) during the session, when executing the smart playback functions, it is necessary to restore the target image contents to the appropriate condition before commencing the playback routine. In this study, this is achieved by using an indexing scheme designated as three-level indexing hierarchy (TIH) to search for the appropriate cut-in point in the session and to identify the commands which should be applied to restore the current image contents to their original condition at the cut-in point. In the proposed indexing scheme, the performance of the cut-in point determination process and the content restoration procedure is enhanced by maintaining a link between all the changes which take place in the image contents over the duration of the session and the commands which induce these changes. The evaluation results confirm that TIH outperforms existing scene-based retrieval systems in terms of both an improved computational efficiency and a lower storage requirement.

Bluetooth telemedicine processor for multichannel biomedical signal transmission via mobile cellular networks

One of the emerging issues in m-Health is how best to exploit the mobile communications technologies that are now almost globally available. The challenge is to produce a system to transmit a patient's biomedical signals directly to a hospital for monitoring or diagnosis, using an unmodified mobile telephone. The paper focuses on the design of a processor, which samples signals from sensors on the patient. It then transmits digital data over a Bluetooth link to a mobile telephone that uses the General Packet Radio Service. The modular design adopted is intended to provide a "future-proofed" system, whose functionality may be upgraded by modifying the software.