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The first ultrasound images of the fetus were published in June 1958.1 The Lancet article by Ian Donald, John MacVicar and Tom Brown occasioned a great deal of interest and comment, in Britain and abroad. However, the scanner that Brown had built for Donald was not much more than an experimental mock-up. The images it produced were of variable quality. Image resolution and definition left much to be desired. It was obvious, especially from Brown’s engineering perspective, that much technical improvement remained to be accomplished . In this chapter, we follow the further development of the contact scanner, culminating in the production of a commercially marketable model. We are particularly interested in how technical problems were solved and how the technology became “black-boxed,” so that a detailed knowledge of how the scanner worked was no longer required of its operators. Donald was, by early 1958, intensely enthusiastic about the potential of compound B-scan to provide two-dimensional representations of the abdominal cavity. The new technique posed exciting challenges for the clinicians as they sought to interpret the images and relate them to clinical decision making . Brown, however, was often not happy with the way scanning was being performed. To achieve consistent results, the ultrasonic probe had to be moved steadily across the patient’s abdomen. This motion was twofold: the probe was repeatedly swung through an arc of approximately 60 degrees, while slowly traversing the abdomen (see fig. 6.1). As noted in chapter 6, the bed-table scanner was formidably inconvenient to use. The operator had to crouch beside the patient’s bed, turning his head to view the screen while simultaneously reaching upward, through the frame of the bed-table, to apply the probe to the abdomen . He was at considerable risk of bumping his head on the underside of the frame and would often have olive oil (used for acoustic coupling) running Chapter Seven The Automatic Scanner and the Diasonograph The Automatic Scanner and the Diasonograph 145 down his sleeve.2 Achieving the necessary consistent motion of the probe was not easy under these circumstances. When first put into service, the scanner was equipped with three oscilloscope screens. One was for A-scope, another was a short-persistence B-scan screen with a camera mounted in front, and the third, also B-scan, was a longpersistence screen with which the operator could monitor the echoes received from the patient’s abdomen and follow the development of the image. The clinicians watched the third screen with fascination as the outlines of reflective surfaces gradually appeared. Such avid attention to the emerging image was often counterproductive. If some feature happened to catch the operator ’s interest, he tended to dwell on that part of the scan, eager to see as much detail as possible. Localized overexposure of the photographic film was often the result. This posed a serious problem because, at this time, the clinical usefulness of each scan greatly depended on the quality of the photographic record, if only because MacVicar and Brown needed to have concrete evidence to show Donald. After vigorous exhortation failed to remedy the clinicians’ scanning faults, Brown responded by removing the B-scan monitoring screen from the apparatus. Henceforth, the operator would have to rely solely on the A-scan display for confirmation that echoes of sufficient strength were being received. MacVicar and Donald protested at the imposed modification , but Brown was adamant that the quality of the final image would be improved.3 It did improve—but not as much as Brown had hoped. Even after removal of the long-persistence screen, results remained uneven. Although conscious of the awkwardness of the prototype scanner, Brown “found it difficult to decide whether problems or apparent inconsistencies were due to equipment variations , or to operator-related causes.”4 He was also painfully aware that with clever manipulation of the electronic settings, the operator could make the oscilloscope image take on virtually any appearance that he wanted. This was one of the reasons why, when building the bed-table scanner, Brown had deliberately not put identifying labels on its control knobs. He wished to ensure that he had to be present during its use and so could standardize, to some extent , the electronic conditions of each scan. Nevertheless, Brown remained a frustrated spectator at the scanning sessions, a proud inventor unable to participate fully in the deployment of his own invention and feeling that, as a result , its performance was not...

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