ml croscope 



1 mage 

 dl ssectf 

 opt 1 ca 1 

 head 



□- 



r - 



rrul t ! pi ler 

 phototubes 



pulse 



amp I I f ler 

 channel s 



Digitizing 

 Single Pulse 

 Selector 



i 



pul se 

 counter 



Fig. 1 



MK.KORADIOGRAPHY 



pulse converter 

 pulse width 



a n al yz e r 



multi- 

 channel 

 pulse width 

 recorder 



count a number of blood cells, for example, 

 in a much larger field than is provided by 

 observation of a single area through the 

 microscope. 



As several authorities have pointed out, 

 large numbers of single, quantitative ob- 

 servation events which can be gathered at 

 great speed by an automatic microscope 

 have a total content of significant infor- 

 mation that a human observer simply can- 

 not obtain in any reasonable length of 

 time. The basic principle of operation is a 

 quantitative digitized pulse enclosing the 

 whole desired element of measurement 

 within a single instrument-selected or in- 

 strument-processed pulse, which becomes 

 the information signal. The advantage of 

 the digital-computer automatic microscope 

 lies in the fact that it can measure, compute 

 and interpret at the rate of thousands of 

 single observations per second as compared 

 with 50 or 100 observation events that the 

 microscopist can study in a reasonable 

 period. The operation of these electronic 

 circuits is a consequence of the radiation- 

 observing properties of Geiger, proportional 

 and scintillation counters. The block dia- 

 gram of the first commercially produced 

 instrument, the Micrometron (Optronic Re- 

 search, Inc., Cambridge, Mass.) is shown in 

 Figure 1. 



Routinely it can count 10,000 blood cells 

 in 10 to 20 seconds. When used as a counter 

 it can take the place of 6 to 10 hematology 

 technicians with an accuracy equivalent to 

 the averaged result of the count of 20 hu- 

 man observers working simultaneously on 

 the blood specimen from a single patient. 



As a research instrument it can establish 

 unequivocal diagnostic indices or basic 

 standards of toxicity levels, or study fluores- 

 cence of nuclei of cells or their spectral ab- 

 sorbance under widely varying conditions. 

 Unquestionably also a wide variety of in- 

 organic and industrial materials may be 

 routinely observed, measured and controlled 

 by such a technique. In the words of Rovner, 

 one of the developers of the micrometron, 

 "It is exciting to realize that the individual 

 blood cells have the quahties of a digitized 

 scanning modality, probing into contact 

 with every living cell in the human organism, 

 and that we can now study them in large 

 enough numbers to learn a great deal more 

 of what they are trying to say." 



REFERENCE 



1. Rovner, Leopold, "Microscopy: Automatic," 

 Medical Physics, Vol. Ill, p. 369, Year Book 

 Publ. Inc., 1960. 



G. L. Clark 



Microradiography. See x-ray microsocopy, p. 56i 



469 



