Blood, phlegm, yellow bile, and black bile – 2,400 years ago, Hippocrates of Kos, arguably the best-known physician in history, suspected that bodily fluids influenced our health. With his doctrine of the “humors,” he and his followers paved the way for the systematic study of bodily fluids.
They believed that many diseases were caused by imbalances in the humors. Based on this belief, physicians developed a diagnostic method that would remain one of the most important tools used in medicine from antiquity well into the early modern era: using the senses to examine the urine. A practitioner of this discipline, known as uroscopy, observed the color and consistency of the urine and assessed its smell – and, occasionally, even the taste.
Advances in chemistry, most especially in the 19th century, ultimately led to more accurate, more reliable methods of urinalysis. But even as late as the 1930s, this kind of analysis was laborious and time-consuming. To determine blood glucose levels as a test for diabetes, the patient’s urine had to be mixed with tracing fluid in a test tube and heated over a Bunsen burner. That did not change until 1941, when the first rapid test for urinalysis was introduced: The Clinitest, from a company called Miles, consisted of an effervescent tablet that changed the color of the urine, thereby making the sugar content visible. Fifteen years later, the first test strips were launched on the market under the Clinistix name. They were even easier to handle, making them the first such solution to be efficient for use at hospitals and medical offices. The strips were standardized, so physicians could read and compare them easily. Over time, numerous other tests were introduced to do things like monitor a patient’s immune system or diagnose hepatitis. These kinds of test strips are still the first method doctors use to gain an overview of the patient’s condition when presented with many symptoms today.
Automatic, large and small
Over the history of modern laboratory diagnostics, the number of tests has risen from year to year. To be able to cope with the many samples involved, the New York-based company Technicon developed an initial automatic analyzer back in the 1930s, significantly reducing staff workloads. The machine could accomplish in one night what had previously taken lab technicians days of work. Numerous systems from different manufacturers followed. Large facilities processed hundreds of samples in just a short time, while small units were used at medical practices, inside ambulances, or right at the patient’s bedside. The Siemens SILAB system from the late 1960s, for example, had a modular structure. The user put the system together according to his or her requirements, with a whole range of options encompassing everything from small microscope workstations to large-scale automated labs. Modern systems, large or small, now analyze urine, blood, and tissue samples within just a short time.
Laboratory diagnostics today and tomorrow
A mere suspicion in antiquity has grown into an accurate, broad-based science advanced by astonishing discoveries, especially in the past 75 years. The pioneering work done by two companies, Miles and Technicon, made a major contribution to this. Today, both companies – or, to be more precise, the companies that grew out of their laboratory diagnostics divisions – are part of Siemens Healthineers. Siemens combines values from the lab with other test or scan results, such as the images produced by ultrasound systems or through computed tomography (CT) or magnetic resonance imaging (MRI) technology. In the future, lab tests will be even more meaningful. A technique known as molecular diagnostics, for example, can be used to determine any patient’s individual predispositions for certain diseases and which medications will be most helpful for that patient.