Automating Blood Pressure Measurements: The Division of Labour and the Transformation of Method

Abstract

To what extent can computers undertake `human' tasks, and what role do people play when computers begin to do `their' jobs? This paper offers an empirical analysis of the scope of medical computers in everyday applications, using, as a vehicle for investigation, a machine that is designed to detect and measure human blood pressure (BP). The paper describes experiments using `novice' volunteers who, following written instructions, attempted to measure BP with a traditional sphygmomanometer. Producing reasonable results proved extremely difficult: the procedure is inherently complicated. It is clear that more experienced staff also deviate from the ideal instruction-based model: variations in techniques and results are widespread. But fieldwork shows that the machine, introduced to standardize the process, is successful: it produces acceptable readings that are comparable over time. The paper investigates how the machine is able to do this. I argue that the division of tasks between human and sphygmomanometer, and between human and computer, has changed. The computer now performs what was previously a human task — but only a slice of the overall task. Furthermore, the computer uses a technique that is different from that traditionally used by people. The task is transformed during its automation. I suggest why some other tasks may be suitable for computerization, and why some that are not should remain essentially human, social activities.