Professor of Obstetrics and Gynecology, Columbia University, College of Physicians and Surgeons
JAMA 63(11):947, Sept. 12, 1914
To the different varieties of incubators which have been in use for many years there have been three common objections: insufficient air space; insufficient circulation of air; and difficulty in maintenance of a constant temperature.
Impressed with these objections I have sought to overcome them:
1. By having the incubator built several times larger than those in common use.
2. By maintaining a gentle current of filtered air passing through it. The air enters through a gauze screened opening below and is sucked out by a small electric fan above.
3. By maintaining a constant temperature by different series of electric lights which may be turned on or off in series.
This incubator, which was built for me by the Hospital Supply Company of New York, and of whose hearty cooperation I wish to express my appreciation, has now been in use with two of its fellows at the Sloane Hospital for Women for one year. It has met its requirements well; has demonstrated its superiority over the old types of incubators with small chambers heated by a water tank to which a gas burner was applied, and in the growth and development of the premature babies kept therein has proved a most valuable addition to the hospital.
The mechanical description of the incubator is as follows:
It is built entirely of steel finished on the outside in aluminum bronze and painted on the inside with gray enamel. It consists primarily of the incubator proper which is 84 1/2 inches in length, 46 1/2 inches in height, and 30 1/2 inches in depth. It is supported on legs 30 inches high, making the total height 76 1/2 inches. In front at each side are two double doors of beveled plate glass set in nickel-plated glass frames. At each end is a beveled glass-plate window 24 1/2 inches by 20 1/2 inches. In the interior directly behind each set of doors is a basket or cradle, built of nickel-plated brass wire and supported on hooks, in which the infant lies. Beneath each cradle is a tray which contains water for keeping the air moist. The condition of the air is indicated by a hygrometer and its temperature by a thermometer, both of which are visible through the glass doors. Beneath each tray is a series of violet-colored incandescent lamps which furnish the heat which is distributed by means of a heat disbursor. On the roof of the incubator a small motor with a fan and the necessary resistance is enclosed in a metal chimney leading from the interior. The motor is controlled by a rheostat situated outside of the incubator between the two front windows. The lamps are connected in series of two on each side controlled by snap switches (as shown in the illustration) which in turn are connected with the house current. Directly inside of each door is a small pilot lamp. When the incubator is in operation the air enters through the intakes, comes in contact with the heat-disbursing plates and passes throughout the interior. By means of the motor fan a continual gentle current of fresh warm air is kept circulating through the incubator. The degree of heat is regulated by turning on more or less of the snap switches and by proper regulation of the motor.
Infant incubator; 1, resistance lamp; 2, heating lamps (violet); 3, motor for exhausting air; 4, thermometer; 5, hygrometer; 6, air intake; 7 humidity tray; 8, cradle; 9, motor regulator; 10, heating lamp switches; 11, pilot light.