Contruyendo La Esperanza

History of Engineering and Technology in Health Care Modern medical care is centered upon the use of a broad range of equipment and medical devices, resulting in an increasing demand for workers with technological expertise. This reading emphasizes the interdependence of medical device technology and those who manage that technology. Highlighting the significant milestones in medical devicedevelopment over the past century serves to illustrate the increasing symbiotic relationship between medical device technology and those who must support that technology, the clinical engineers, biomedical equipment technicians, physicists, and equipment maintenance personnel. The Early 1900s A minor hospital building boom significantly increased the number of hospitals in the United States. However,the principal means of providing health care was still physicians making house calls and carrying their “little black bags.” In general, physicians seemed to be in short supply, but so was the demand for their services. Many of the services that the physician provided also could be obtained from experienced amateurs in the community. The home was typically the site for treatment and recuperation,and relatives and neighbors constituted an able and willing nursing staff. At the time, the average life expectancy was 47 years, and 95% of all births were in the home, although only 15% of the homes had a bathtub. The leading causes of death were pneumonia, influenza, tuberculosis, and dysentery, followed by heart disease and stroke. The first X-ray machines were introduced following Roentgen’sdiscovery of X rays in 1895. Early radiographs involved large doses of radiation. An image of the human head could require up to 11 minutes of exposure time. The first use of contrast media occurred between 1906 and 1912. Dutch physiologist Willem Einthoven introduced the first ECG recording device, a string galvanometer, in 1901. Because it used a very large magnet, it was large and heavy,weighing about 600 lbs. The first “telecardiogram” was recorded on March 22, 1905, when Einthoven transmitted ECG signals from a healthy volunteer in a hospital to the galvanometer in his laboratory, 1.5 kilometers away by way of polemounted telephone cables. The volunteer’s elevated R-waves were attributed to his cycling from the laboratory to the hospital for the recording. The latest technology atthat time was the radio which, following Marconi’s first successful transmissions in 1895, was used primarily for shipto-ship communications.

Pre-1940 During the period between World Wars I and II (1919–1939), the development of medical instrumentation benefited from electronic amplification and the adaptation of technologies that had been developed for other applications. The use of X rays fordiagnosis continued to progress during this period, as did the use of radium needles for the treatment of tumors. Hospitals where radiation treatments were performed began to employ physicists to assist in the treatment planning and safe use of the radiation sources. The development of instruments and devices for diagnosis or medical research was generally undertaken through the collaboration ofphysicians and private entrepreneurs. The use of electronic amplification techniques developed following Lee de Forest’s invention of the triode valve in 1906 led to more compact ECG machines. Sanborn and Cambridge Instruments were early manufacturers of these table- or cart-mounted devices. In 1928, Frank Sanborn’s company (later acquired by Hewlett-Packard) converted its table model ECG machineinto its first portable version, which weighed 50 lbs. and was powered by a six-volt automobile battery. Al Grass contributed to the development of electroencephalography by adapting a lowrequency, high-gain recorder that he had first used to monitor seismic events to charting very small EEG potentials. Arnold Beckman adapted a pH-sensing electrode, which he had developed as a “ripeness indicator”...