Note on the diagnostic and therapeutic value of the Coolidge tube / by Lewis Gregory Cole.

  • Lewis Gregory Cole
Date:
1914
Catalogue details

Licence: In copyright

Credit: Note on the diagnostic and therapeutic value of the Coolidge tube / by Lewis Gregory Cole. Source: Wellcome Collection.

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    beyond the W altei scale. It will be seen that the rays readily passed thro the thickest platinum disc, and even through the surrounding lead. The following tests will show the therapeutic efficiency of the Cooli tube. ^ For these experiments a Hampson radiometer was used. A piec< beffi 2 inches thick was irradiated by a Coolidge tube, at a focus dista °i inches. An aluminium filter 3 millimetres thick was interposed betw the tube and the beef. One Sabouraud pastille was placed on the surface the beef, a second pastille 1 inch below the surface, and a third past under 2 inches of beef. Experiment /.—The tube was regulated so that the parallel sparky v as 7g inches. The Bauer penetrometer indicated far beyond the registe scale. rlhe Walter penetrometer registered 8 + . An exposure of three ; a half minutes was made. During this time the milliamperage varied fi 10 to 8 and back to 9. The pastille on the surface read 12 H., or three tir the erythema dose. The pastille 1 inch deep read 6 H., or one and a 1 times the erythema dose, and the pastille 2 inches below the surface 3 or about three-fourths of an erythema dose. Experiment //.—The spark-gap was again 7| inches, the Walter pe tiometei 8 + , and the milliamperage from 8 to 10. An aluminium fi] millimetres thick was interposed, and a series of four one-minute exposui followed by a two-minute exposure, was made on a similar piece of beef. With a one-minute exposure the pastille on the surface read 4 H. After the second exposure of one minute, making a total exposure of t minutes, a second pastille on the surface read 4 H. The pastille an ir deep, exposed for a total of two minutes, read 3 H. After the third one-minute exposure, a new pastille on the surface agi lead 4 H. The pastille an inch deep, exposed for a total of three minut read 4 H. After the fourth one-minute exposure, a fourth pastille on the surface re 4 Tile pastille an inch deep, exposed for a total of four minutes, read 6 ! and the pastille 2 inches deep read 3 IT. After a fifth exposure of two minutes, the fresh surface pastille read 8 1 he pastille 2 inches deep read 4 H. ! I he above tests show that by using six ports of entry one may obtain nil erythema dose 2 inches below the surface in six minutes. With tl tiemendous amount of highly-penetrating rays, any amount of screenii desirable may be used without prolonging the treatment beyond a reasona! time. It must be noted, however, that the Coolidge tube is like a two-edgt swoid capable of doing great damage unless manipulated with the utmo care. The danger is especially insidious in that there is no evidence of til action of the tube during its operation. With an ordinary focus-tube considerable exposure of several minutes is without danger to the patien it i the full capacity of the new tube, however, serious and even fat; burns may be caused in much less than a minute. A note of warnin