ABSTRACT
A system was developed which allowed the simultaneous communication of digitized, full duplex speech and electrocardiography (ECG) signals in realtime. A single band-limited channel was used over a standard telephone line providing 3 kHz bandwidth. The full duplex speech was compressed to 2400 bit/s using linear predictive coding, while multiple ECG signals were processed by a novel ECG compression technique. Extensive use of digital signal processing reduced the combined bit rate to less than 9600 bit/s, allowing the use of low-cost commercial modems. The ECG communications system was tested in clinical trials. It enabled a hospital-based clinician to provide diagnostic and treatment advice to a remote location over the standard telephone network.
Subject(s)
Electrocardiography/instrumentation , Remote Consultation/instrumentation , Signal Processing, Computer-Assisted/instrumentation , Telephone/instrumentation , Analog-Digital Conversion , Humans , Male , Middle Aged , SoundABSTRACT
Diarrhea may present as an acute transient condition that is hardly more than an inconvenience or as an acute devastating condition that decimates whole armies and cities. In places in which it is endemic, chronic diarrhea may be equally devastating; however, chronic diarrhea is usually the problem of an individual patient. A clinician may require the most extensive analysis for proper appraisal of chronic diarrhea. A thoughtful, thorough history and physical examination will often serve to narrow the number of tests required to reach a satisfactory diagnosis. Rational therapy may then be quickly determined from many existing references.
