A portable ballistocardiograph.
The instrument consists of a pneumatic accelerometer which is worn on the top of the head, secured by a strap under the chin. It is connected by a tube to a sensitive capacitance manometer, the signals from which are amplified and displayed on a meter. Connection can also be made to an ECG recorder to display waveform. The apparatus is battery-operated and fully portable, so that it is possible to record Bcg on patients in their own beds.