Philips Medical Therapy
Up the 19 th century electricity is applied for treatment of specific diseases in medicine. In the course of time a number of therapies are developed.
At the time Philips start working with x-ray technology in 1917, diagnostics as well as therapy was taken into account for medical applications. For therapy Philips has worked since 1918 for a long time with the Antoni van Leeuwenhoekhuis in Amsterdam, a special hospital for treatment of tumours with x-rays.
The group of Dr. Bouwers developed a number of special x-ray tubes and generators capable of handling voltages larger than 250 kV, which were needed for deep x-ray therapy. For superficial and contact therapy, using voltages of about 50 kV, also a dedicated apparatus was developed. Dr. G.J. van der Plaats, physician and working for Philips was one of the driving forces.
||A CT tube, dedicated for contact therapy (about 1940). The focal spot of this tube is located very close to the output window of the tube (focal spot-skin distance of 18 mm). The tube has a radiation filtering of 0,2 mm Al equivalent. The anode voltage is about 50 kV and the tube current is 2 mA. To prevent too much heat at the patients skin, the tube is cooled at the position of the cathode.
UV and IR therapy
Since the second decade of last century physicians start to apply ultraviolet (UV) radiation (wavelength about 245 to 310 nm) for treatment of bacterial diseases, rachitis and lupus (skin tuberculosis).
After some years also infrared radiation (IR, wavelength about 700 to 1400 nm) is used for treatment of rheumatism, lumbago, and muscular pain. From about 1930 onwards, Philips developed a number of products for these applications.
||De Biosol, type number. 11855/03, about 1950.
||The Biosol-MLU, type number 11912/02, about 1955. The spectrum of the radiation consists of UV and IR.
Short wave therapy
Diathermy equipment is used to heat locally parts inside the body. To do so, alternating currents with a frequency of about 1 MHz are applied to the body via skin electrodes.
To improve the penetration of the currents through fat layers, short wave therapy is developed working with a frequency of about 50 MHz.
||The Oscilloflux 2000, type number XM 1000/10, about 1956.
By using high frequency currents, there is no need for direct contact between the current source and the human body. Now the high frequent current can be coupled into the body with plate electrodes, which increase the ease of use of the apparatus.