What is "kymograph"

Kymograph \Ky"mo*graph\, n. [Gr. ? wave + -graph.] (Physiol.) An instrument for measuring, and recording graphically, the pressure of the blood in any of the blood vessels of a living animal; -- called also kymographion.

n. A device that gives a graphical representation of a variation in a phenomenon such as blood pressure over time, using a pen on a rotating drum.

n. scientific instrument consisting of a rotating drum holding paper on which a stylus traces a continuous record (as of breathing or blood pressure) [syn: cymograph]

A kymograph (which means 'wave writer') is a device that gives a graphical representation of spatial position over time in which a spatial axis represents time. It basically consists of a revolving drum wrapped with a sheet of paper on which a stylus moves back and forth recording perceived changes of phenomena such as motion or pressure. It was invented by German physiologist Carl Ludwig in the 1840s and found its first use as a means to intrusively monitor blood pressure, and has found several applications in the field of medicine. Its primary use was to measure phenomena such as changes in muscular contractions or other physiological processes, including speech sounds. Kymographs were also used to measure atmospheric pressure, tuning fork vibrations, and the functioning of steam engines.