CardioNet adapts cell phone, truck-tracking tech to monitor heart patients

Computerworld - CardioNet Inc. has tapped technology -- originally developed by Qualcomm Inc. to track and send messages to large truck fleets -- to help wirelessly monitor heart patients believed to suffer from episodic and hard-to-detect episodic atrial fibrillation.
Larry Watts, vice president of marketing at San Diego-based CardioNet, said atrial fibrillation -- which affects more than 2 million U.S. residents and results in short, butterfly-like quivers in the heart -- is hard to detect because of its transient nature. Unlike a massive heart attack, once an episode of atrial fibrillation is over, it's difficult for a doctor to detect.
CardioNet developed a proprietary PDA-type electrocardiogram (ECG) monitoring device connected by a short-range wireless system operating in the unlicensed 900-MHz band to electrodes on a patient's chest. The PDA receives signals from the electrodes and then transmits the data to CardioNet over a hard-wired telephone system if the patient is at home or through a built-in cell phone chip if the patient is out. CardioNet technicians monitor the data for signs of the heart fibrillation and pass the information onto the patient's doctor.
After a patient has used CardioNet for about two weeks, the doctor has enough information to make a diagnosis of atrial fibrillation and prescribe medication to correct the problem, Watts said. CardioNet can also use the monitoring system for potentially catastrophic events, directing a patient to an emergency room and alerting the consulting physician by phone, fax or e-mail if necessary.
The service is available in Pennsylvania, Indiana and metropolitan Washington and New York.
When CardioNet started offering its service to patients in Pennsylvania a year ago, it originally used Cellular Digital Packet Data (CDPD) technology, which has a maximum data rate of 190.2Kbit/sec. Next week, Watts said, CardioNet expects to complete the transition of its service to Code Division Multiple Access (CDMA) 1Xrtt cellular networks, which have a peak data rate of 144Kbit/sec. and average speeds of 70K to 80Kbit/sec. The network is being operated in cooperation with the OmniTRACS division of Qualcomm Inc. in San Diego.
According to Watts, CardioNet shifted from CDPD technology to CDMA because of its higher throughput and better coverage and reliability. Jeff Vosburg, senior director for strategic business development at Qualcomm's wireless business solutions unit, said his company ensures the reliability of the CardioNet's ECG data with a software messaging protocol originally developed and used by the OmniTRACS truck-fleet tracking and messaging system. That system handles 7 million messages per day from 479,000 trucks.
The messaging protocol is ideally suited for a