Sphygmograph
The sphygmograph or sphygmograph (old Greek "pulse recorder") is a device for the permanent recording of pulse frequencies as curves; it was the first to measure blood pressure without blood.
functionality
In all sphygmographs, the alternately expanding and contracting artery sets a small plate in motion, which in turn acts on a long lever arm. This lever arm writes the movement of the arterial wall on a larger scale on a strip of paper, which is set in uniform motion by a clockwork and is passed in front of the tip of the lever arm. The pulse movements are shown on the paper in the form of a wavy line modified in many ways, depending on the type of pulse being examined. If one knows the speed with which the paper passes the lever tip, one can calculate the duration of a pulse wave; In addition, the gradual rise and fall of the pulse waves, their sequence, etc., can be followed precisely on the curve.
History and Development
The first such device was probably developed by the physiologist Karl von Vierordt (1818-1884) in 1854. The improved replica of the French natural history professor Étienne-Jules Marey from 1860, who later also invented the chronophotographic shotgun , was more widespread . Marey's variant recorded the curves on sooty glass plates. In 1891, Dr. von Frey used a sphygmograph based on Vierordt's principle.
In the medium term, however, the sphygmograph was unable to establish itself and was replaced by the Waldenberg pulse watch from 1877 onwards .
Sphygmophone
A sphygmophone is a subspecies of the sphygmograph. It is a resilient circuit breaker connected to a galvanic battery and telephone, which - placed on the artery - makes the pulse and its modifications audible.
See also
literature
- Paul Emil Flechsig : About a modified application of Mosso's hydro-sphygmograph . Neurol Cbl 1882; 1: 513-514.
- Theodor pull : Sphygmographic examinations on the mentally ill . Jena, 1887.
- Max von Frey: The investigation of the pulse and its results in healthy and sick states (1892).
- Otto Frank: The registration of the pulse by a mirror phygmograph, MMW 50, 2, 1809-1810 (1903).
- Otto Frank with J. Petter: A new sphygmograph , Ztsch.Biol. 49, 70-76 (1907).
- Otto Frank: On the theory of the sphygmograph , Ztsch.Biol. 89, 263-270 (1929).
- Otto Frank: Theory of the air transmission sphygmograph , Ztsch.Biol. 89, 274-288 (1929).
- Dudgeon, RE: The Sphygmograph: its history and use as an aid to diagnosis in ordinary practice . London 1882
