ABSTRACT
Whether in patient monitoring or elsewhere, physicians have similar concerns. When we analyze how a medical doctor-whatever his or her specialty-uses measurements, we notice several things. First, the doctor strives for certainty. Given the great importance of the patient’s health, it is considered a professional failure if an incorrect diagnosis is reached and thus an incorrect therapy is instituted. Thus, the doctor wants to have all relevant information that will enable determination of the appropriate diagnosis. This requires the clinician to have an up-to-date knowledge of what to look for and an up-to-date experience of problems that may arise. It also requires the most informative measurement devices with the greatest accuracies and the lowest error rates. Requirements for measuring devices therefore include guaranteed accuracy: a welldesigned instrument will indicate when it cannot present an accurate number, and not present an inaccurate or random number. Instruments should not mislead the clinician. It is often possible to arrive at the correct conclusion when a piece of evidence is missing, but not when incorrect information is believed to be accurate. A device must also present its results in such a way that no confusion is possible regarding the numerical values. This calls for good ergonomic design and a certain degree of simplicity in the presentation of results.
