100 C O R P O R A T E T E C H N O L O G Y | M i c ro s c o py a n d I m a g i n g Te c h n i qu e s
Innovations from Siemens range from the first pro- duction-standard electron microscope in 1939 (be- low) to the world’s fastest CT (right). In 1974, Siretom created an image in five minutes (photo strip, cen- ter). Today, the Somatom Sensation 64 provides a 3D picture in seconds (right).
VIEWS OF THE SMALLEST WORLDS
Microscopy and imaging techniques revolutionized medicine and materials sciences in the 20th century. Innovations from Siemens broke new ground in these areas — and helped to advance technologies ranging from electron microscopy and ultrasound to computer and magnetic resonance tomography.
O ur first steps into the micro- cosmic world were not easy. When Ernst Ruska invented the electron microscope at the Berlin Technical University in 1931, no one could believe that electron beams and magnetic lenses could be used to visualize objects — much as light rays can, but with up to a thousand times greater resolution. Yet even if it were, in fact, possible, they said, wouldn’t the energy-rich beam traveling with nearly the velocity of light de- stroy any organic objects in an in- stant? There was enormous skepti- cism. Until 1936, Ruska was therefore primarily concerned with the question of “where to get a million reichsmarks” to refine his
“Übermikroskop” and produce it in quantities. Together with Bodo von Borries, a friend of his who was equally convinced of the fu- ture of the invention, he gave dozens of presentations and wrote countless letters. Siemens was the first company to recognize the po- tential of the new microscope. It assumed the financial risk and set up an electron optics lab for the researchers in Berlin in 1937.
After that things moved quickly. Ruska and von Borries de- veloped a production-standard in- strument in only two years. In 1939, the world’s first commercial electron microscope was put to use at Farbwerken Hoechst, a
30,000-fold magnification, dye pigments could be analyzed in the minutest detail. By the end of the war, 30 additional instruments had been built, and Ruska’s brother Hel- mut presented the first images of a bacteriophage.
In 1953, Siemens brought out the legendary “Elmiskop I,” which was far superior to all other instru- ments on the market. The new technology became firmly estab- lished not only in biology, chem- istry and medicine but in solid state physics and materials sciences as well. “Whether it be semiconductor components, designer materials or nanoparticles, without the electron microscope there would be no mi- crotechnology or advanced materi-
als,” says Helmut Oppolzer, head of the Analytics Center at Siemens Corporate Technology.
In medical engineering, too, the Corporate Research Group achieved groundbreaking innovations with Medical Solutions. In 1965, for ex- ample, Richard Soldner astounded the scientific community with Vido- son, the world’s first real-time ultra- sound device for medical diagnos- tics. It rendered the images immediately in half-tones. For the first time, doctors were able to ex- amine details of soft tissues and watch the movements of individual organs or an unborn child on a monitor. Prior to 1965, high-fre- quency sound waves were mostly used in materials testing. Soldner
paved the way for the use of ultra- sound in medical technology.
“Together with Corporate Re- search, we were able to replace the time-consuming multiple-pass scanning necessary to make a sec- tional view with a single scan. We reduced the image formation time by more than two orders of magni- tude,” recalls Soldner. One of his colleagues from Corporate Re- search was Bernd Granz. Working in Erlangen in the mid-1960s, Granz helped devise the first ultra- sound array systems, which are now state of the art. Their advan- tage: They make possible portable, flexible systems by means of a large number of tiny ultrasonic transduc- ers arranged side by side. Says Granz: “Today, some two-dimen- sional arrays can be manufactured
with silicon technology in a single step. With these, you can depict 3D volumes inside the body in real- time.”
Since the early 1970s, computer tomography has likewise enabled completely new insights. Its tomo- grams have shown much finer con- trasts than the shadowgraphs of conventional X-ray technology. In 1974, Siemens began marketing Siretom, the first computer tomo- graph produced by an X-ray equip- ment company. The machine’s un- derlying idea was that an X-ray source revolves very rapidly around the patient, who lies on a table. De- tectors on the other side of the pa- tient measure the X-rays that pass through the body and forward the
CO R P O R AT E
data to a computer that calculates tomograms from it. Modern ma- chines measure several slices at a time — 64 in the case of the So- matom Sensation 64. Siemens owes its leading market position in this field also to researchers from Corporate Technology, who have developed special ceramic detec- tors and improved the 3D image processing (Pictures of the Future, Fall 2004, p. 68).
Another revolutionary technol- ogy is magnetic resonance tomo- graphy. MR technology was in- vented in the 1940s. At first, it served as a means of analyzing molecules, but it can also be used to create images of the inside of the body. Essentially, MR measures the distribution of hydrogen atoms. Building a device of this kind re-
In the future, diseases will be diagnosed even earlier, using tech- nologies such as molecular imag- ing. With these techniques, physi- cians will be able to observe both anatomical changes and metabolic processes. In the case of cancer, that means they could track down not only tumors but, at an earlier stage, individual cancer cells that have a pathological metabolism.
Siemens researchers have al- ready implemented this principle in the form of positron emission to- mography (PET). Hundreds of de- tectors identify the radiation emit- ted by a previously administered short-lived radioactive contrast medium.
In addition, developers are ex- amining new methods that rely on light in the near-infrared range. This
quired expertise in fields such as superconductivity, high-frequency engineering and micro-electronics.
Friedrich Gudden, former re- search director for imaging meth- ods at Medical Solutions, recalls the development of the first MR tomo- graph in the early 1980s. “When we needed help, Corporate Re- search was there, especially when it came to strong magnetic fields. The researchers used what they knew about these fields for other areas too, like generators and the mag- netic levitation train.” The most re- cent example of such cooperation is the Magnetom Tim machine, which delivers whole-body images of outstanding resolution thanks to new coil technology.
requires new optical fluorescent techniques and contrast media — called “Smart Contrast Agents” — that fluoresce only when they come into contact with their target mole- cule — for instance a tumor-specific enzyme.
“At Siemens, we know a lot about imaging techniques,” says Mohammad Naraghi, head of busi- ness development at Medical Solu- tions. Yet this competence must be supplemented by knowledge of pharmacology and molecular biol- ogy in particular, he says. “So we’re working with external partners, in- cluding renowned academic re- search institutes, pharmaceutical c o m p a n i e s a n d b i o t e c h f i r m s . ” ■ L u i t g a r d M a r s c h a l l
PIONEERS OF MICROSCOPY
Ernst Ruska (1906 – 1988) and Bodo von Borries (1905 – 1956). Ernst Ruska discovered the princi- ple of electron microscopy while still a student. In 1931, he built the first working electron microscope in Berlin with Bodo von Borries and Max Knoll. In 1934, von Borries be- gan working for Siemens in Berlin. At the electron optics lab, he and Ernst Ruska finally succeeded in developing the electron micro- scope to a production level in 1939. Ruska received the Nobel Prize for Physics in 1986.
FATHER OF ULTRASOUND
Richard Soldner (born 1935). At 15, Richard Soldner began an apprenticeship as a toolmaker at the Siemens-Reiniger plant in Er- langen. In 1955, the company awarded him a scholarship to study high-frequency engineering. Working in the Electromedical Sys- tems department, Soldner de- signed the first prototype of a real- time ultrasound machine for medical diagnostics in 1962. In 1968, he and his colleagues devel- oped the first electronic linear ar- ray, which enabled production of easily portable ultrasound devices. Three years later, he succeeded in focusing the ultrasound beam dy- namically and thereby created the basis for the high image quality achieved today (p. 74). In 2004, Soldner received the Ian Donald Medal of the International Society of Ultrasound in Obstetrics and Gy- necology for his pioneering work.
Pictures of the Future | Fall 2005