Every child knows that you can create much better hand shadow puppets when the sun is shining than when it is cloudy, because hand shadow images work best when you have a bright single-point light source. The same is true for X-ray imaging, only this time you need body-penetrating X-rays, not light, to perform the trick. Right from the start, Philips saw the potential.
A suitable X-ray source (X-ray tube) is little more than a glass vacuum bottle with two metal electrodes in it, one of them heated (the hot cathode) so that it ‘boils-off’ electrons. Put a high enough voltage between the electrodes and the electrons accelerate towards the second electrode (the anode) hitting it with enough energy to create X-rays.
Having repaired X-ray tubes during the First World War at the request of Dutch physicians, something that drew on its expertise in manufacturing glass light bulbs, Philips began small-scale manufacture of its own X-ray tubes in 1919. Recognizing the possibilities in medical imaging, it went on to acquire German company C.H.F. Mueller, an existing X-ray tube manufacturer that had unique expertise in focusing X-rays in the direction you want them to go. Coupled with Philips’ own technology to shield against stray radiation, it delivered exactly what was required for medical imaging – a focused X-ray beam that could be directed at the patient without risking long-term radiation exposure to radiologists. From there, Philips went from strength to strength in terms of its commercial offerings, delivering the first portable X-ray machine, the first high-power rotating anode X-ray tube, the first X-ray image intensifier for rapid viewing, and the first C-arm machine for easy image capture. To this day, the Röntgenstraße site on which the first Philips/Mueller joint venture was built remains a core element in Philips’ healthcare innovation ecosystem, housing both its Hamburg research laboratories and its DACH headquarters.
While steady progress in X-ray imaging continued over the years, it was not until the 1970s, with the introduction of affordable computing power and digital storage, that things really took a quantum leap forward. And once again, Philips was in the vanguard of this change.