7.2.1 Introduction

Abstract

The development, understanding, and use of standards is an important component of a clinical engineer's activities. Whether involved in industry, a health care facility, governmental affairs, or commercial enterprise, one way or another, the clinical engineer will find that standards are a significant aspect of professional activities. With the increasing emphasis on health care cost containment and efficiency, coupled with the continued emphasis on patient outcome, standards must be viewed both as a mechanism to reduce expenses and as another mechanism to provide quality patient care. In any case, standards must be addressed in their own right, in terms of technical, economic, and legal implications. It is important for the clinical engineer to understand fully how standards are developed, how they are used, and most importantly, how they affect the entire spectrum of health related matters. Standards exist that address systems (protection of the electrical power distribution system from faults), individuals (means to reduce potential electric shock hazards), and protection of the environment (disposal of deleterious waste substances). From a larger perspective, standards have existed since biblical times. In the Book of Genesis [Chap. 6, ver. 14], Noah is given a construction standard by God, " Make thee an ark of gopher wood; rooms shalt thou make in the ark, and shalt pitch it within and without with pitch. " Standards for weights and measures have played an important role in bringing together human societies through trade and commerce. The earliest record of a standard for length comes from ancient Egypt, in Dynasty IV (circa 3000 B.C.). This length was the royal cubit, 20.620 inches (52.379 cm), as used in construction of the Great Pyramid. The importance of standards to society is illustrated in the Magna Carta, presented by the English barons to King John in 1215 on the field at Runnymede. Article 35 states: " There shall be standard measures of wine, beer, and corn—the London quarter—throughout the whole of our kingdom, and a standard width of dyed, russet and halberject cloth—two ells within the selvedges; and there shall be standard weights also. " The principles of this article appear in the English Tower system for weight and capacity, set in 1266 by the assize of Bread and Ale Act: " An English penny called a sterling, round and without any clipping, shall weigh thirty-two wheatcorns in the midst of the ear; and twenty ounces a pound: and eight pounds do make a gallon of wine, and eight gallons of wine do make a bushell, which is the eighth part of a quarter. " In the United States, a noteworthy use of standards occurred after the Boston fire of 1689. With the aim of rapid rebuilding of the city, the town fathers specified that all bricks used in construction were to be 9 × 4 × 4 inches. An example of standardization to promote uniformity in manufacturing practices was the contract for 10,000 muskets awarded to Eli Whitney by President Thomas Jefferson in 1800. The apocryphal story is that Eli Whitney (better known to generations of grammar school children for his invention of the cotton gin) assembled a large number of each musket part, had one of each part randomly selected, and then assembled a complete working musket. This method of production, the complete interchangeability of assembly parts, came to be known as the " armory method, " replacing hand crafting, which at that time had been the prevailing method of manufacturing throughout the world.