Abstracts

RATIONALE: To develop and test a wireless portable system for real-time remote display of ongoing EEG at any location. Background: Emergency EEGs and continuous EEGs are increasingly utilized to evaluate obtunded patients in ICUs and emergency rooms. Timely review and interpretation of such studies is necessary, and often requires the immediate availability of an electroencephalograher. Review of digital EEG has been limited to on-site interpretation or off-site review using computers with wired network or Internet access. A portable system capable of displaying real-time or near real-time EEG from any location is desirable, and would facilitate EEG use in emergency or critical care settings.
METHODS: A secure Web server was established which provided high-resolution images of in-progress and previously acquired EEG data. Using commercially available software, techniques were developed for wirelessly connecting to the web-server using several portable computers and a widely available CDMA cellular network with nominal data transmission speed of 14.4 K/sec. A portable system[ssquote]s EEG display capability was first evaluated to determine its clinical utility for visual review. The best machine configuration was then tested 10 times by transmitting one minute segments of high resolution 21 channel EEG over a wireless CDMA cellular network. Transmission speed was also determined for the best device configuration over a 512 K/sec symmetric DSL connection, and for a Pentium III 966 MHz machine directly connected to the EEG web-server over a LAN.
RESULTS: The optimal configuration consisted of a lightweight (1.6 kg) PIII 700 MHz notebook PC running Windows 2000 with a 12.1 inch diagonal display at a resolution of 1024 by 768 pixels. This system provided good EEG review resolution; a palm-size PC had inadequate display size for easy review of EEG, and a Windows CE handheld PC with 800 by 600 pixel display provided intermediate resolution and performance. Weight of the optimal wireless system was about 1.8 kg. Transmission time for a 60 sec EEG segment averaged 92 sec (range 75-115 sec) for the PIII portable PC using wireless CDMA cellular data transmission, and 2 sec (range 1.5-2.0 sec) for the same device over the DSL connection. A PIII 966 MHz machine on a LAN required less than 0.5 sec for each 60 second EEG download.
CONCLUSIONS: Remote review of in-progress EEG data using a widely available portable wireless system is currently feasible. Wireless emergency review of moderate amounts of EEG (minutes) can be readily accomplished with existing hardware and software. An expected 10-fold increase in cellular network data transmission rates, and a readily predictable doubling of processor speed in ultralight portable computers, should make remote wireless EEG review both very rapid and clinically useful by 2002.
Disclosure: Grant - Persyst Development Corporation.