A kymograph (from Greek κῦμα, swell or wave + γραφή, writing; also called a kymographion) is an
analog device
Analog devices are a combination of both analog machine and analog media that can together measure, record, reproduce, receive or broadcast continuous information, for example, the almost infinite number of grades of transparency, voltage, r ...
that draws 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
A stylus (plural styli or styluses) is a writing utensil or a small tool for some other form of marking or shaping, for example, in pottery. It can also be a computer accessory that is used to assist in navigating or providing more Accuracy an ...
moves back and forth recording perceived changes of phenomena such as motion or pressure.
The kymograph was initially a mechanical and hydraulic device, invented by German
physiologist
Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical ...
Carl Ludwig
Carl Friedrich Wilhelm Ludwig (; 29 December 1816 – 23 April 1895) was a German physician and physiologist. His work as both a researcher and teacher had a major influence on the understanding, methods and apparatus used in almost all branches ...
in the 1840s, and found its first use as a means to monitor
blood pressure. The blood pressure was conveyed by hydraulics and levers to move a stylus that scratched a white trace into soot-covered paper on the revolving drum. Time is represented by the drum's rotation rate, and was recorded by a further stylus driven by a clock or tuning fork. The kymograph almost immediately became the central instrument in physiology and physiology education. Throughout the nineteenth and twentieth centuries, researchers and technicians devised many improvements to the device, plus numerous new sensory components to measure a wide range of physiological phenomena such as breathing, muscle movement, speech. New detection and registration systems included electrical and electronic methods, and plotted in ink.
Kymographs were also used outside medical science to measure atmospheric pressure, tuning fork vibrations, the functioning of steam engines, animal habits and the movement of molecules in cells.
Kymography in experimental Physiology
The kymograph is generally used to study the effects of
xenobiotics
A xenobiotic is a chemical substance found within an organism that is not naturally produced or expected to be present within the organism. It can also cover substances that are present in much higher concentrations than are usual. Natural compo ...
on tissue preparations. It is a standalone recording apparatus used alongside other apparatuses such as organ baths. Writing levers are used to trace the recording from muscle contractions. Some of the commonly used writing levers are the simple lever, the frontal writing lever and the starling heart lever. These writing levers are connected to a
fulcrum
A fulcrum is the support about which a lever pivots.
Fulcrum may also refer to:
Companies and organizations
* Fulcrum (Anglican think tank), a Church of England think tank
* Fulcrum Press, a British publisher of poetry
* Fulcrum Wheels, a bicy ...
which is found on a secondary apparatus.
See also
*
Videokymography
*
Depth kymography
References
Medical imaging
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