Seeing Inside the Body: Electronics Aids Medicine

Abstract

The relationship between muscles, including those of the heart, and electricity had been known since Galvani’s experiments in the 1780s, or possibly even before. However, in 1887, Augustus D. Waller at St Mary’s Medical School in London showed that electrical signals of the heart could be monitored from outside the body.¹ He used a capillary electrometer, invented in 1872 by French physicist Gabriel Lippmann, to measure the signals.² This was a crude device where a column of mercury met sulfuric acid and the meniscus between the two would move when a current flowed from one liquid to the other. The result was recorded on a moving photographic plate.

Every year, more than 300 million X-rays, CT scans, MRIs and other medical imaging exams are performed in the United States, and seven out of ten people undergo some type of radiologic procedure.

Charles W. Pickering