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Arterial Pressure Waveform Analysis
Published in Wilmer W Nichols, Michael F O'Rourke, Elazer R Edelman, Charalambos Vlachopoulos, McDonald's Blood Flow in Arteries, 2022
While we prefer to use the transfer function process in clinical and drug studies, this is a convenience, and all relevant data are present in the radial waveforms themselves (Rietzschel et al., 2001a). Such waveforms, unprocessed, were used in studies of endothelial function (Hayward et al., 2002) and drug action (Millaseau et al., 2002). An alternative way to measure aortic systolic pressure comes from measurement of the beginning of the late systolic shoulder (Pauca et al., 2004; Takazawa et al., 2007; Takazawa et al., 2012; Takazawa, 2015; Kobayashi et al., 2016). This is widely used in Omron and other Japanese devices and is available as an option in SphygmoCor and similar devices. Results are virtually identical with both methods; this can be confirmed by inspection of radial and aortic pressure waves in the sphygmograph report.
Medicine, Technology and Industry
Published in Roger Cooter, John Pickstone, Medicine in the Twentieth Century, 2020
A struggle between competing intellectual approaches more obviously affected the reception of the electrocardiograph, developed by Dutch physiologist Willem van Einthoven at the turn of the century. The attempt to graphically represent the dynamic function of the heart was not original to Einthoven. Marey had invented a ‘sphygmograph’ to record pressure changes in the heart in 1860. Produced by one of France’s leading precision watch-makers, the sphygmograph was widely known. What Einthoven did was to develop a much more sensitive galvanometer for recording the heart’s electrical activity. Unlike the Roentgen apparatus Einthoven’s instrument was very difficult indeed to build. And unlike Roentgen, Einthoven took a keen interest in its production. When other physiologists wanted him to build similar instruments for them Einthoven, who did not wish to see his workshop become a manufactory, sought a company to manufacture the instrument. After an approach to Siemens and Halske proved abortive, Einthoven reached agreement with Munich instrument maker Max Edelmann in 1903. Edelmann would manufacture and market the galvanometer and would pay Einthoven a royalty for each one sold. When, in early 1907, Edelmann found that he could improve on Einthoven’s design he stopped paying the royalty. Disturbed and upset, Einthoven refused to have anything more to do with Edelmann, and approached Horace Darwin, youngest son of Charles and a director of the Cambridge Scientific Instrument Company (CSIC).
Early Vascular Ageing
Published in Giuseppe Mancia, Guido Grassi, Konstantinos P. Tsioufis, Anna F. Dominiczak, Enrico Agabiti Rosei, Manual of Hypertension of the European Society of Hypertension, 2019
Peter M. Nilsson, Stéphane Laurent
In a historical perspective, the interest in arterial function and stiffness contributing to hemodynamic changes predates the clinical measurement of blood pressure and diagnosis of hypertension as we know it. In London, UK, the physician Frederick Akbar Mahomed carried out studies on pulse wave properties in arteria radialis with his own constructed sphygmograph, and published in 1877:It is very common to meet with people apparently in good health who have no albumen in the urine, who constantly present a condition of high arterial tension when examined by the aid of the sphygmograph (5).
Historicizing Technological Hegemony
Published in The American Journal of Bioethics, 2023
Let us now turn to consider tools used to examine the heart. Abnormalities of the pulse have long been recognized as the harbingers of bad health, or even death. Physicians learned how to feel the radial pulse, how to observe the jugular pulse, and how to draw inferences both from direct observation and from the use of a tool—the sphygmograph—that transformed the movements that were palpable with the fingertip and seen with the eye into lines on a smoked drum. After Willem Einthoven invented the electrocardiogram (ECG) machine in 1902 it became possible to record the electrical currents associated with the heartbeat from outside the body. Like the X-ray, this machine attracted widespread attention, perhaps most notably by Thomas Lewis (later Sir Thomas Lewis), who brought an ECG machine from Einthoven’s laboratory in the Netherlands back to University College, London. Lewis, a physician, authored numerous articles and books about the ECG, founded a new journal on heart disease, and was a well-respected clinician at a top hospital in what was arguably the city with the most advanced medical care in the world. For over a decade Lewis built his career by studying how to use the ECG. He showed how one could use the ECG accurately to differentiate between more and less morbid sorts of arrhythmic abnormalities. It’s hard to overstate the ways in which Thomas Lewis towered over all other physicians who were interested in heart disease (Lewis 1925).