RF-transmitted CsI radio-isotopic ambulatory recorder for left ventricular ejection fraction monitoring.

We have developed a CsI multidetector probe in order to produce a nuclear ambulatory recorder to study simultaneously cardiac electric activity and the left ventricular ejection fraction. To make the device lighter, the electronics were designed with surface-mounted technology, and a serial data RF transmission system was used. The data are processed on a real-time basis using a portable microcomputer. Unlike other commercially available devices, this monitor avoids the problems of volume, weight, recording time capacity and slow off-line data processing. Our device permits global and regional analysis of the ejection fraction for a moderate manufacturing cost. It is intended primarily for ambulatory use and can easily be adapted to perform a monitoring function. The first tests on patients conducted using the prototype demonstrate the technical reliability and satisfactory operation of the device.