TY - JOUR
AU - Cooley, A. G.
AB - Telognosis J. Gershon-Cohen , M.D. and A. G. Cooley 255 S. 17th St. Philadelphia 3, Penna. Excerpt The term “telognosis” is used to abbreviate the three terms—“teleo roentgen diagnosis”—indicating roentgenographic diagnosis obtained from facsimiles of original roentgenographs transmitted by radio or telephone wires over short or long distances. More and better hospitals are the aim not only of small rural communities, but also of the medical profession and government alike. One of the most difficult problems raised in the functioning of a good rural hospital is the successful operation of a clinical and x-ray laboratory. At present, the part-time attendance of an experienced radiologist from the nearest large urban center is secured, but this arrangement necessitates waste of much time in travel, sometimes over long distances. The newspaper services solved the problem of rapid long-distance transmissions of picture facsimiles over commercial telephone wires and there seemed to be some reason to believe that a similar service could be developed for roentgenography. Description of Apparatus This system of long-distance roentgenographic facsimile via commercial telephone wires or radio has been developed by one of us (A.G.C.), and has been used routinely in the field for two years, over a distance of twenty-eight miles between the Chester County Hospital, West Chester, and Philadelphia, Penna. The transmitting equipment (Fig. 2) consists of a glass drum around which film of any dimensions, up to 14 × 17 inches, can be clamped in place. This cylinder is 5 inches in diameter and 18 inches long. It rotates at a uniform speed of 180 r.p.m., while a small beam of light is focused onto the film. The illuminated or elemental area measures 1∕50 of a square inch (Fig. 1). Light passing through the film is picked up by a photocell inside of the glass cylinder. This photocell is connected with a pre-amplifier for building up the picture signal before it is passed on to an output amplifier connected to the telephone line or radio transmitter. Over a modern voice frequency circuit, 2,700 elemental areas can be transmitted per second. This corresponds to approximately one square inch of the original x-ray film. Under normal operating conditions, a 14 × 17-inch film is transmitted in four and one-half minutes. Smaller films can be transmitted in correspondingly less time. Several smaller films can be transmitted at the same time by combination on the transmitting cylinder. After the 2,700 cycle tone is fed into the photocell circuit, the light on the photocell modulates the tone so that the output to the pre-amplifier varies in amplitude in accordance with the light passing through the film. The strength of the signal into the telephone circuit is the same as the signal produced by an ordinary telephone voice transmitter.
TI - Telognosis
JO - Radiology
DO - 10.1148/55.4.582
DA - 1950-10-01
UR - https://www.deepdyve.com/lp/radiological-society-of-north-america-inc/telognosis-pNzRK8IAk0
SP - 582
VL - 55
IS - 4
DP - DeepDyve
ER -