An instrument for recording the form, strength, and variety of the pulse of the heart.

Sphygmograph

An instrument for recording the form, strength, and variety of the pulse of the heart.

A sphygmograph applied to an arm.

Sphygmograph

A sphygmograph applied to an arm.

A variation of a sphygmograph.

Dudgeon's Sphygmograph

A variation of a sphygmograph.