X-Rays for Surgery

E. J. Northrup Building a Machine in This City

WITH MANY NEW FEATURES

Dr. Totman Is Interested and the Machine Is Likely to Be Used at St. Joseph’s.

It is probable that surgeons at St. Joseph’s hospital will soon have for their use in operations at the hospital an X-ray machine of the alternating current type, apparatus which, though of recent invention, is an essential to the equipment of a modern hospital. Such a machine is being built by F. F. Northrup, assisted by Charles Noxon. Mr. Northrup is the son of A. Judd Northrup and an electrician of standing. He and Mr. Noxon expect to have the machine completed this week. The cost will be about $300. The work is progressing under the direction of Dr. D. M. Totman of St. Joseph’s surgical staff, the members of which will doubtless have the benefit of its use.

The machine embodies several new features. It is small for the length of spark which it gives, 13 inches long by nine wide and 10 high. It is of the alternating current type and the discharge is noiseless, overcoming one of the main objections to this type of machine. The discharge is copious and capable of exciting the longest type of X-ray tubes to their full capacity. It is constructed without the use of oil, and oil is generally an objectionable feature in machines of this type. It may be attached to any alternating current socket. The machine is put up in a handsome box of highly polished cherry and has an external current regulator for exciting the tube to any desired intensity. Improvement in the X-ray machines has been rapid and this one will embody the best points in all with several features altogether new. About three miles of fine insulated wire are required.

The X-ray machine is recognized today as a necessary part of hospital equipment. With its aid difficult fractures may be easily studied, especially fractures at the wrist and elbow, and may be easily set. The healing process can be observed without the necessity of removing the bandages. With the aid of the X-rays the location of foreign bodies in the flesh may be easily discovered. The machine is used in two ways, by the aid of the fluoroscope by which the fracture or foreign substance may be observed directly with the eye, or by the photographic plate, by which a photograph of the fracture may be secured as a permanent record. The fluoroscope is especially useful for a rapid preliminary examination, but for clear images, especially of deep fractures, the photographic plate is preferred. Both may be used in this machine. In order to use the machine it is only necessary to follow explicit but not intricate directions. A technical knowledge of electrical science is not necessary.

“One objection to the X-rays has been that they burn the flesh,” said Mr. Northrup yesterday. “Where burning occurs it is owing to the carelessness or ignorance of the physician. In the hands of a competent man there is no danger from the machine whatever.” Mr. Northrup gave an instance where he saved a woman’s arm which had been poorly set after being broken. By the use of the machine the blunder in setting was made apparent.

There are several types of machines which are suitable for exciting the X-rays in a Crookes’s vacuum. The static coil was employed at first. Now the induction coil or the Tesla high frequency coil, so called, are used. There is small choice between these two, the induction coil being used where a direct current is available, the Tesla coil where the current is alternating. The machine being built is of the Tesla high frequency type because the current at the hospital is alternating. The potential at the hospital is 52 volts, which will be first transformed by means of a high potential transformer to 25,000 volts and again transformed by oscillatory discharge sent through a Tesla coil to 250,000 volts, the latter being passed through the X-ray tube.

Mr. Northrup explained how erroneous is the popular notion that danger rests where the voltage is high. “What determines the injury from a shock,” he said, “is the quantity of the current. One-half ampere may be a fatal dose. The quantity of the current which will pass through the body in any given case is determined by two facts, the electromotive force along the entire circuit and the resistance of the entire circuit. It may therefore be meaningless to say that a person took 250,000 volts. This statement becomes accurate if it is said that a person takes a certain current. The current received in all X-ray machines of this type is small, so small as to be harmless.”