. Medical diagnosis for the student and practitioner. several of the instrumentsare capable of registering three tracings of different origin simultaneously. The spring lever type of recorder may be used for the radial and a specialreceiver over the heart itself. The simultaneous records of greatest use and value are those of the venousand carotid pulse and to obtain these the patient is placed in the dorsal THE POLYGRAPH AND POLYGRAM 499 position, with the head slightly flexed, turned to the right* and restingupon a small pillow and should retain the posture for several minutes beforerecord-t
. Medical diagnosis for the student and practitioner. several of the instrumentsare capable of registering three tracings of different origin simultaneously. The spring lever type of recorder may be used for the radial and a specialreceiver over the heart itself. The simultaneous records of greatest use and value are those of the venousand carotid pulse and to obtain these the patient is placed in the dorsal THE POLYGRAPH AND POLYGRAM 499 position, with the head slightly flexed, turned to the right* and restingupon a small pillow and should retain the posture for several minutes beforerecord-taking is attempted. If the venous pulsations are not evident in the jugular fossa because ofoverdistension of the veins, it may be necessary for the patient to sit up beforethey can become manifest. In some cases of phlebosclerosis or extreme venouspressure no proper record is obtainable. Technic.—Ordinarily the venous pulse is evident and the proper receiveris placed over the jugular bulb in the interval between the two heads of the Jugular Fig. i88.—Mackenzie ink polygraph. This instrument records two simultaneoustracings only, , radial pulse and one other, such as carotid, jugular, apex beat, etc., thegreat advantage being the avoidance of smoked paper and the convenience and permanencyof the ink tracings which may be continued almost to any length from the long roll of papersupplied with the instrument. The instrument need not be attached to the patients wristand by many is preferred because of this feature. The clock work operates at varied andcontrolled rates, permitting the taking of protracted records at different speeds. Theoriginal instrument was invaluable, but Dr. R. Edwin Morris has improved greatly the con-trol of the paper strip, increased the ease and accuracy of tambour attachment and adjust-ment, and, furthermore, has made possible a delicate, independent and accurate control ofthe pens, through various ingenious devices.* sterno-mastoid, just a
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectdiagnos, bookyear1922
