Computer programmes for the medical man: a solution.

The application of electronic computers to medical problems offers roseate visions, which the experts are busily working towards. Even ordinary medical research workers and clini-cians are beginning to understand some of the possibilities, and a few of them are even beginning to think that these machines might be of help to them in their everyday work. Unfortunately, when they try to find out something about the practical use of electronic computers they come up against difficulties. This is true even for those who are acquainted with programmers, or can get in touch with computing installations. It is the purpose of this paper to give an account of these difficulties and to provide a solution. How a Computer Works A digital computer is a device for manipulating symbols. These may represent the digits of arithmetic, or they may be symbols of logic. It is a " general purpose " device, and will deal with specific tasks only when it is first "adjusted" to do them. This adjustment is known as programming. The programming of these machines was at first extremely complicated , and only the expert could do it. It became obvious that the process had to be simplified, and this was done by dividing the procedures into two stages. The first is to write the programme in a simple form, in a " language " easy to understand and use; and then to write another programme which will " translate " the first into a form that will actually operate the machine. The latter programme is called a " comp ler," and once it has been designed and tested it can be fed into the machine and stay there permanently. The prospective user of the machine has merely to learn the simple language and write his programme with its aid. Since the simplified language requires only a few weeks to learn, this marked a great step forward in making the machines accessible to computer " laymen." 1 In actual practice the advance was not so great. It is easy to write a programme, but it is difficult to write one correctly. A computer cannot work if a programme has errors, and the compiler includes procedures for checking that a programme is correctly punched. When an error is found, the machine stops and prints appropriate symbols, which enables the programmer to find the errors. These may be (to the human A …