Localizing Needle Fragments in the Tissues of the Body by Means of Magnetism; Demonstration
George H. Monks
Boston Medical and Surgical Journal
Dr. Monks called attention to the fact that in certain cases in which needles, or needle fragments, are buried in the tissues of the body, the use of magnetism may help the surgeon in localizing the foreign body. In order to use the magnetic test it is necessary first to magnetize the buried needle, and then, by means of a delicate magnetized indicator of some kind, to localize it. To magnetize a buried needle an ordinary steel magnet usually suffices, and for an indicator a fine magnetized
... le suspended at, or near, its middle by a fine silk thread or even by a human hair. A very small compass may also I be used. The magnetic test is apparently only applicable in those cases where the buried fragment is large, and near the skin. The technie of the method was then demon-strated, and a box containing a number of needle-fragments which had been localized by magnetism, and removed from patients, was passed about for inspection. Accompanying this box were fine magnetized needles attached to delicate silk threads, for use in applying the magnetic test to the needle fragments in the box. DISCUSSION. Dr. W. M. Boothby, Boston: The apparatus devised by Dr. Monks is excellent for locating small elongated bodies, like needles, lying only a short distance below the skin. It may be of interest to bring to your attention an apparatus recently devised by Prof. Bergonie of Bordeaux for locating fragments of shrapnel imbedded in the deeper tissues. While we were at the American Ambulance Hospital, Paris, Prof. Bergonie demonstrated the apparatus to the Harvard Unit. The apparatus consisted of an electric magnet of considerable power and a motor for rapidly reversing the direction of the electric current. When the electricity flowed in one direction the magnet would attract; when flowing in the opposite direction it would repel the steel or iron fragment. The rapid reversal of the magnetic force set the foreign body into vibration and the palpating finger of the surgeon could locate the body as being directly beneath the point of maximum vibration. By using a sterilized point the exact location could be reascertained after the incision was made and the surgeon was working in the approximate region of the shrapnel fragment.