A vibration recorder for pathological analyses

The author describes a new device which has been developed for pathological use in recording the hand tremors of patients, as an aid in the diagnosis of disease. The motion is resolved into its horizontal and vertical components, both of which are given on the record. This instrument is also useful to the engineer for recording mechanical vibrations of various kinds. An important feature is the freedom of the vibrating body from all restrain, due to the optical method employed.