This device is used to record patient heart conditions on a circular 4-channel magnetic disc—among other EKG functions. The box contains quite a few recordings. Some are examples that come with the unit and others are from patients that have notations of the condition and dates ranging from 1964-65. This custom device was made for Dr. Samuel H. John Jr., M.D. It is in very nice condition and looks complete. Machine turns on. Heart monitor works. Discs placed on playback show recorded heart EKG visually on screen. I haven’t had chance to listen to the recordings but I am sure this unit is operational once studied a bit—but not fully tested. A very fascinating evolution in heart treatment technology and recording tech.

This is an exceptional example and great for a research collection or any medical tech museum. These machines date from circa 1935-1955 and this one appears to be from the late 1950’s

Made by the Cambridge Instrument Company Wooden cabinet contains a 4-channel magnetic disk heart sound recorder with frequency accentuation, separate player and playback volume control, combined record volume patient monitor, and playback switch; input for two stethophones, one EKG, patient, R wave, cathode ray; 5 controls located above input, inset at front of case; boxes of circular tapes, and stethophone microphone.

Dr. John was born in 1924 and worked in family practice until his retirement. This was in his personal collection