Biography

Etienne Marey began his medical studies at the Faculty of Medicine in Paris around 1850. By the time he started his internship at the Cochin Hospital in the mid-1850s he had decided he would devote his career to research in physiology. In particular he wanted to study the nature of biologic movement through the use of graphic recording techniques. In his 1859 doctoral thesis he used the rotating smoked-drum kymograph, developed a dozen years before by Ludwig, to study pulse waveforms and transmission. He took to using the term sphygmograph for his device (sphygmos being a Greek word meaning pulse).

His first major work was in collaboration with a French veterinarian Jean Baptiste Auguste Chauveau and together, in 1861, they elucidated the nature of the apex beat. At that time there was controversy as to whether the visible and palpable apical impulse was due to ventricular filling in late diastole or due to systolic contraction. They resolved the issue by simultaneously recording the apex beat movement and pressures in the right atrium and right ventricle in an awake horse using elastic balloons attached to catheters as motion and pressure transducers. Access to the right heart chambers was by way of the external jugular vein. Each movement or pressure change generated a pulsation within the air-filled catheters and was, in turn, transmitted to a rotating smoked-drum sphygmograph. Their finding that the apical impulse was caused by early forceful ventricular contraction was acclaimed by a specially convened committee of the French Academy of Science in 1862 and it remains a milestone as the first graphic recording of intracardiac events.

In the next two years they also studied left ventricular pressure waveforms, using retrograde access to the left ventricle from the carotid artery, and characterized various phases of the cardiac cycle, including what is now known as the isovolumic phase of left ventricular contraction. Marey's 1863 book 'Physiologie Medicale de la Circulation de Sang' details the methods they used.

While Chauveau then turned his attention to other fields, including microbiology and biochemistry, Marey continued to improve on his graphic recording equipment. He used this equipment to study many issues in physiology, after 1868 becoming particularly interested in human and animal locomotion. One device, 'Marey's tambour' permitted subtle movements to be tracked and recorded with minimal interference with the subject and it was used by physiologists until the 1950s. He explored the nature of cardiac excitability and, in 1876, determined that the heart could be excited by an electrical stimulus only during diastole. In 1896 he described the unexcitable phase of the cardiac cycle as the 'refractory period'.

In the last 20 years of his life he made extensive use of cinematography in the study of animal movement and he promoted the standardization of recording techniques to avoid confusion amongst researchers. An institute was established in Paris during the 1890s to address this latter issue and it was later named the Institut Marey. In recognition of his remarkable contributions in graphic recording he was nominated President of the Academie des Sciences in 1898.

There might be no better characterization of his philosophy than the one he himself gave in his book 'La Methode Graphique dans les Sciences Experimentales et Principalment en Physiologie et en Medicine'(2nd Edition, 1885):

"Science meets with two obstacles, the deficiencies of our senses to discover facts and the insufficiency of our language to describe them. The object of the graphic methods is to get around these two obstacles; to grasp fine details which would be otherwise unobserved; and to transcribe them with a clarity superior to that of our words."