The sphygmograph in America: writing the pulse

The sphygmograph (literally a "pulse writer") was 1 of the first "instruments of precision" to be used in examining the cardiovascular system. In the 1860s and 1870s, some physiologically oriented American practitioners began using European sphygmographs to evaluate patients with a variety of cardiovascular and other disorders, study the action of drugs, assess arterial tension, and determine what was referred to as the "state of the circulation." Three previously unrecognized Americans modified existing European models or constructed original instruments of their own design. Two of these American "sphygmograph men" published the results of their novel experimental work, and the third produced a successful commercial model. Despite early expectations that the sphygmograph would reveal precise information about cardiovascular disease, the various models proved frustrating to use in practice. Recorded sphygmograms defied precise interpretation and correlation with clinical and pathologic findings. The sphygmograph, which faded from practice by the 1890s, helped prepare practitioners for more durable technologies such as the sphygmomanometer and electrocardiograph, which entered practice early in the 20th century. The sphygmograph and its American champions were overshadowed and quickly forgotten.