Design and evaluation of a pneumatic pulse monitor for use during magnetic resonance imaging

We describe a portable, battery-operated instrument designed to monitor pulsations in the finger or toe. The monitor is based on pneumatic principles and is suitable for use in the electromagnetically harsh environment of magnetic resonance imaging. A compliant Silastic chamber is deformed with each cardiac pulsation; the resulting pressure wave is then transmitted along a 25-ft (7.5-m) microbore tube to a pressure sensor in a remote electronic monitor.