US3470866A - Portable incubator - Google Patents

Description

OGL 7, 1969 s. B. GITTELSON 3,470,866

PORTABLE INCUBATOR Filed Nov. 1e, 1966 s sheetss11eet 1 Z7 f j WAH 4ms/fm' 0%./ y l ifm/Way- Oct. 7, 1969 s. B. GITTELSON 3,470,866

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' PORTABLE INCUBATOR Filed NOV. 16, 1966 3 Sheets-Sheet 5 w l Ilf 'Ilm United States Patent O 3,470,866 PORTABLE INCUBATOR Stanley B. Gittelson, 1445 Merrick Ave., Merrick, N.Y. 11566 Filed Nov. 16, 1966, Ser. No. 594,891 Int. Cl. A61b 19/00; A01k 31/14 U.S. Cl. 128--1 6 Claims ABSTRACT F THE DISCLOSURE This invention concerns a portable incubator for infants, of novel construction designed to enclose the infant within a radiantly heated atmosphere having precisely controlled conditions within predetermined ranges and, when necessary the proper degree of oxygen enrichment.

The following is given as background:

Under usual nursery conditions, radiant loss accounts for approximately two-thirds of the total heat loss of an infant. The effects of radiation losses are of considerable importance in the establishment of neutral thermal conditions. The temperature measured in incubators is the ambient air; since radiation is a function not of air temperature but of the surrounding objects (incubator wall, room wall, windows, etc.), losses by this means are not taken into consideration merely by measuring incubator air temperature. The effects of radiation can be shown by two examples: if `an incubator wall is chilled by proximity to an air conditioner or, more commonly, to a window at night, a baby can lose considerable heat despite a constant warm incubator air temperature; conversely, hyperthermia readily occurs with little or no change in air temperature if an infant is inadvertently placed in the sunlight.

An important difference between the infant and adult is the greater thermal conductance of the infant. This is apparently due to less tissue insulation, not to a difference in vasometer control, since the vasometer response to the cold has been shown to be well developed in newborn infants and animals. The Jeffect of an increased thermal conductance is a warmer skin temperature which in turn, results in greater heat loss by convection and radiation. Because of the relatively large surface area and the increased thermal conductance, the neutral temperature for infants is higher than for adults at otherwise comparable environmental conditions.

In recent years careful studies of survival rates have demonstrated the importance of maintaining normal skin temperature with infants of low birth weight, with respiratory distress syndrome or other disease states where further metabolic stress is to be avoided. Important too, may be precise control of body temperature in the delivery room and during transport to the nursery.

At present, many infants falling into these categories are transported by an ambulance to certain medical centers which specialize in their care. A trip by ambulance to such a medical center may involve one to two hours. In cool weather, despite a heated ambulance and previously known portable carriers these babies may arrive at their destination with body temperature down to a highly dangerous F.

As hereinbefore stated, the problem is that two-thirds of the heat loss in the infant is due to radiant heat loss because of large relative body surface area, poor body insulation and the inability of infants for a certain period to increase their ability to produce enough heat by themselves to sustain life.

The need for a properly designed highly effective portable incubator for the transportation of infants has existed for a long time. The present invention provides a highly effective portable incubator of novel construction which satisiies this need.

Among the objects of this invention are: To provide a highly effective lightweight portable incubator which maintains the temperature of the walls and roof of the container surrounding the infant during transportation at about 93.4 F. while maintaining the infants skin tem perature at 96 F. and the ambient or air temperature in the container at about 89 F. but not exceeding 93.2 F.; to provide a portable infant carrier which is designed to be heated during transportation and whose walls and roof are made of thin sheet metal, such as aluminum, having the characteristics of rapid heat conduction and excellent heat reflecting surfaces, surrounded by light weight plastic insulation such as styrene or vacucel; to provide a portable relatively light weight incubator having an outer container or box provided with sheet metal walls, and an inner infant carrying container or box provided with sheet metal walls and roof, both containers being surrounded by insulation and adapted to be separately heated from different sources of electric energy, and with the inner container fitted with suitable temperature sensing devices; to enable the safe transportation of an infant over a relatively long period of time by means of a portable incubator providing a confined atmosphere having controlled conditions of wall and ambient temperatures.

Briefly stated, the invention comprises a portable light weight infant incubator having an outer and a removable inner container both provided with separate heat sources. The outer container has four thin sheet metal walls and a bottom provided with a heat source or upon which a heating source is adapted to rest. The inner container in which the infant is placed rests upon the interior bottom surface of the outer container and is provided with four walls and a cover or lid .all made of thin sheet metal and all in good thermal conductive contact with one another. The sheet metal used in both containers is capable of rapid heat conduction and has excellent heat reflecting surfaces thereby providing radiant heat to the interior of the container. One such metal is highly polished aluminum. The inner container is also provided with a heat source, such as an elongated resistance wire mounted on the cover or lid and adapted to be energized from a battery. Both inner and outer containers are separately provided with heat insulation on the outsides thereof, such as by lightweight plastic material containing air cells therein. Temperature sensing devices are used to indicate the wall and ambient temperatures of the inner container and means are provided for maintaining these temperatures within a desired range. The outer container is provided with a cover, preferably hinged to the top of one side wall, and a handle for enabling the complete incubator including both cotnainers to be carried by hand.

Other features and objects of the invention will appear in the following detailed description in conjunction with drawings, wherein:

FIG. 1 is a front elevation view of the portable incubator of the invention with the cover of the outer container closed and latched;

FIG. 2 is a cross-section of the incubator of FIG. 1 along the line 2 2, and shows the inner and outer insulated cotnainers resting one within the other;

FIG. 2a is a detail showing how the lid of the inner container conductively and thermally engages the walls of the inner container;

FIG. 3 is an exploded View of FIG. l and shows the outer container with its cover in the open position and the inner container above the outer container. A portion of the inner container is shown broken away to disclose the interior thereof;

FIG. 4 is a top or plan view of the incubator of FIG. 1 and shows the handle for carrying the portable incubator and the two portals which also serve as air vents for the outer container;

FIG. 5 schematically illustrates the electrical wiring for the portable incubator of the invention and shows the two sets of cords for individually supplying electrical heating energy to the respective containers.

Throughout the figures of the drawing the same parts are represented by the same reference characters.

The portable, lightweight incubator of the present invention comprises an outer container or box and an inner container or box 12 within which the infant rests. The outer container 10 has a main box-like body portion 11 and a cover 13 hingedly connected thereto at 14. A handle 16 at the top of the cover 13 permits the entire incubator to be carried by hand. A pair of latches are provided to tixedly hold the cover 13 in its closed position. The four walls W and the cover 13 of the outer container are thin sheets of polished aluminum which rapidly conduct heat and have excellent heat reflecting surfaces. These aluminum walls W and the aluminum cover 13 are all in good thermal engagement as may be noted from FIGURES 2 and 3 which show the cover provided with edge areas which conductively contact the metal walls. The inner container includes four walls W' and a cover or lid 17 all made of thin sheets of polished aluminum having the same characteristics of rapid heat conduction and excellent heat reflecting surfaces as the walls of the outer container. The lid 17 is provided with spaced aluminum extensions 18 along its two long sides for conductively engaging the top portions of the aluminum walls W' to enable heat to pass rapidly as possible from the lid 17 to the walls W. Both outer and inner containers 10 and 12 are surrounded with lightweight but effective heat insulation 19, such as styrene or vacucel, preferably composed of a multiplicity of air cells contained in compressed plastic material. In the closed position of each container, the aluminum cover or lid is in good thermal conduction contact with the aluminum walls thereof.

The cover 13 of the outer cotnainer 10 is provided with a pair of portals or vents 20 for enabling the air in the interior thereof to pass therethrough, and also any electrical wiring, as may be required for control purposes -to pass therethrough. Similarly, the lid 17 of the inner container 12 is also provided with a pair of portals or vents 21 for the same purpose. The inner container 12 as shown in the exploded view of FIG. 3 provides a vent space between the tops of the aluminum walls W and the lid 17 at each end of the lid 17 when the lid 17 is in closed position on the walls W', due to the V-shaped nature of the lid. If desired, the lid 17 of the inner container may be hingedly fastened to one long side of the top wall of the inner container in the same manner as the cover 13 of the outer container is hingedly fastened to its container.

The inner container 12 is provided with a sheet metal bottom B upon which and spaced therefrom by an air space is an apertured sheet metal plate 22. The apertured sheet metal plate 22 is made to be appreciably thicker than the bottom B and the side walls W for supporting a matress or pad 23. Note FIGS. 2 and 3. The infant rests on the mattress or pad 23 within the inner container.

Both the outer and inner containers are heated from separate sources of electrical energy. The heating unit for the outer container 10 is any suitable means on the metal bottom thereof, as for example, a hot plate H sold under the trademark Hotray which is connected to a conventional electrical cord 24 in turn provided with a prongtype plug 25 for insertion into the house mains supplying volts, 60 cycles, alternating current. The inner container 12 is provided with a conventional elongated heating unit 26 mounted on top of and in a U-shaped depression formed in the aluminum lid sheet 17. The heating unit is designed to be heated from a battery, such as a 12 volt battery in an automobile, by means of an electrical cord 30 having a suitable plug 27 for insertion into the electric cigarette lighter outlet of the automobile. Obviously, the battery for heating the unit 26 need not Be intimately connected with the autmobile ignition system and the electrical cord 26 and plug 27 represent any suitable electrical connection from the heating unit to a source of electrical energy such as a battery or dry cell that can furnish the required voltage for about three hours.

When the inner container 12 is inserted into the outer container 10 the bottom B of the inner container rests upon and is heated by the heater H. The air space between the bottom B and the apertured metal plate 22 assures that the plate 22 does not rest directly upon the heater and hence does not produce hot spots above the mattress 23 such as which might occur if a direct stream of hot air flowed regularly against one spot. The uniformly spaced holes in the metal plate 22 assures that the radiant heat owing through the air space and through the holes in the metal plate 22 uniformly heats the mattress and the infant lying on the mattress. The distance between the bottom B and the apertured plate 22 of the inner container may be one inch,

One end of the outer container 10 is provided with means, such as brackets or straps 28, for supporting a source of oxygen indicated at O which may take the form of a pressure tank of oxygen. The same end of the outer container 10 is provided with an oxygen entry opening 292, such as a nipple for connection of a hose from the source of oxygen. The pressure tank is provided with the usual metering valve, flexible tubing, and dial mechanism (or flow meter), to determine, under control, the amount of oxygen which passes into the incubator and into the inner container. Since methods of achieving this result are known, no claim per se is being made to this particular feature as part of the present invention.

The electrical circuitry for the two heating units H and 26 are shown in FIG. 5. The heater H resting on the bottom of the outer container and in contact with the metallic bottom of the inner container may be a conventional type such as an A.C. heater, 250 watts, drawing 2.2 amperes of current, and suitable for use with 110-115 volts alternating current house mains. The heater 26 for the lid of the inner container may also be a conventional type direct current heater, such as a 12 volt D.C. heater, 46 watts, drawing 3.75 amperes of current and suitably insulated from an electrical standpoint from the aluminum lid 17. In circuit with the 12 volt electrical wiring, there is provided a temperature sensing element or probe 31 which, is adapted to be placed on the babys stomach to maintain the abdomen at a fairly precise temperature of 96 F. within half a degree. This temperature sensing element may be a thermostat which opens the electrical circuit to the heater 26 whenever the skin temperature exceeds a safe value or may be a thermistor having a dcsired temperature coetlicient to increase the electrical resistance of the thermistor and reduce the current drawn by the heater 26 when the skin temperature rises and vice versa Such a thermistor may be one made by Cole- Palmer of Chicago, Ill. or Fenwal 53600-0 thermistor with 71900 probe made by Fenwal of Ashland, Mass.

A shielding window 32 in the main body of the outer container enables the viewing of a pair of thermometers 33, 34 on the inside of the incubator, one thermometer 33 measuring the wall temperature of the inner container and the other thermometer 34 measuring the ambient or air temperature of the inner container. The inner wall thermometer 33 is mounted on one wall W' of the inner container while the ambient thermometer 34 is connected by capillary tubing and a probe to the interior of the inner container. This probe may hang or dangle in the interior between the surrounding lwalls W from tubing extending through one of the ports 21. The insulation 19 is removed at the location of the thermometers to permit visual inspection thereof from the outside of the thermometer. Obviously, if desired, the thermometers 33, 34 may be so arranged and suitably located on the lid 17 to permit visual inspection through the portals 20 of the outer container. Since the details of connecting such thermometers to perform the above functions are conventional, no detailed illustration has been given in the interest of simplicity of illustration so as not to detract from the clarity of the drawings.

Small signal lights 35, 36 are shown in FIG. 5 wired in conventional manner in parallel with the heaters H and 26 to afford visual evidence of the fact that these heaters are electrically operative whenever such is the case during operation of the equipment. These lights may be located at any convenient place on the incubator. Thus the lights will turn on when their respective heaters are on, and will be olf when no electrical current is being supplied to their respective heaters.

In the operation of the incubator of the invention when it is desired to transport an infant therein, the portable incubator is started up by energizing the outer box heater H until the ambient temperature of the inner container 12 and the wall temperature of the inner container 12 reach the desired temperatures 89 F. (but not exceeding 93.2 F.) and 93.4 F., respectively, as measured by thermometers 34 and 33, respectively. At this point, the infant can be placed Within the inner container upon the mattress 23, the probe 31 placed upon the infants stomach next to skin and the lid 17 closed. The controls using the temperature sensing devices will maintain an abdominal skin temperature of about 96.1 F. The outer cover 13 is then closed and latched, the plug 25 disconnected from the house mains, and the incubator hand carried by its handle 16 into the heated ambulance at which time the inner container heater 26 is connected to the l2 volt car battery. The infant will receive radiant heat from the -walls and lid of the inner container until the ambulance reaches its destination at which time the incubator can be disconnected from the car battery and hand carried into the hospital or house.

By way of example only, the overall dimensions of the outer container including cover 13 and insulation but excluding the oxygen tank may be 22" long, 15 wide and high, while the dimensions of the inner container including cover and insulation may be 18" long, 11.5" Wide and 10.5 high. The weight of the incubator exclusive of oxygen tank may be about 20 lbs. A prematurely born infant may weight anywhere from 2-5 lbs. more or less.

Suitable apparatus may be incorporated or attached to the incubator of the invention for controlling conditions of humidity, and a portable lightweight suction machine operating on a l2 volt or 6 volt battery may also be incorporated in the design of the invention.

What is claimed is:

1. An incubator having inner and outer containers, said inner container being adapted to support an infant therein, and individual heating elements for said containers the interior walls of both said containers and said covers comprising thin metallic sheets providing rapid heat conduction and excellent heat reflecting surfaces, said metallic Walls and cover of each container -being in thermal engagement with one another, there being insulation on the exterior surfaces of said metallic sheets, said electrical heating elements for said inner and outer containers having different power capabilities, the heating element for said outer container being designed for connection to house electrical power main while the heating element for said inner container is mounted upon and heats one of said interior surfaces of said inner container and designed for a direct current battery source of electrical energy, whereby radiant heat is provided by the interior walls and cover of said inner container upon energization of the heating element for said inner container.

2. An incubator having inner and outer containers, said inner container being adapted to support an infant therein, and individual heating elements for said container, both of said containers being provided with covers, the walls and covers of both said containers comprising thin metallic sheets providing rapid heat conduction and excellent heat reflecting surfaces of said metallic sheets, there being insulation on the exterior surfaces of said metallic sheets, said electrical heating elements for said inner and outer containers having different power capabilities, the heating element for said outer container being mounted in the interior and on the -bottom of said outer container and -being designed for connection to house electrical power mains while the heating element for said inner container is designed for a direct current battery source of electrical energy, said inner container having a metallic bottom resting on the heating element for said outer container, and a temperature sensing device in circuit with the heating element of said inner container for controlling the temperature in said inner container, both of said covers having air vents therein.

3. An incubator having inner and outer containers, said inner container being adapted to Suport an infant therein, and individual heating elements for said container both of said containers being provided with covers, the walls and covers of both said containers comprising thin metallic sheets lproviding rapid heat conduction and excellent heat reflecting surfaces, there being insulation on the exterior surfaces of said metallic sheets, said electrical heating elements for said inner and outer containers having different power capabilities, the heating element for said outer container being mounted in the interior and on the bottom of said outer container and being designed for connection to house electrical power main while the heating element for said inner container is designed for a direct current battery source of electrical energy, said inner container having a metallic bottom resting on the heating element for said outer container and also having an apertured plate mounted above and spaced from said metallic bottom for supporting a mattress, and a temperature sensing device in circuit with the heating element of said inner container for controlling the temperature in said inner container, both of said covers having air vents therein, said heating element for said inner container being mounted adjacent to the exterior surface of the metallic sheet constituting the cover for said inner container, whereby an infant resting on said mattress will receive radiant heat from the sheet metal walls and cover of said inner container when the heating element for said inner container is energized, and means for measuring the wall and ambient temperatures of said inner container.

4. An incubator having inner and outer containers, said inner container being adapted to support an infant therein, and individual heating elements for said container, both said containers being provided with covers and exterior insulation for said containers and covers, a temperature sensing ydevice in circuit with the electrical heating element for said inner container for controlling the temperature in said inner container, said temperature sensing device comprising a body contacting element adapted to contact the infants abdomen, said incubator being portable and lightweight, the walls and covers of said containers comprising thin metallic sheets providing rapid heat conduction and excellent heat reflecting surfaces, said insulation being a plastic material provided with air cells, said covers having air vents therein, said heating element for said inner container being of a size capable of being heated by a relatively low voltage battery, and thermometers for measuring the wall and ambient temperatures of said inner container.

5. A portable incubator comprising a container adapted to support an infant, said container having a heat source therefore, said container having thin metal sheet walls and thin metal bottom and cover sheets, all in thermal engagement in the closed position of said incubator, said metal sheets being made of a material which rapidly conducts heat and has interior surfaces which highly reflect heat, said heat source being adjacent at least one of said metal sheets, and insulation on all exterior surfaces of said metal sheets, whereby said walls, bottom and cover are kept at a predetermined temperature during enerigization of said heat source to prevent loss of radiant heat from the infant, a second heat source positioned adjacent to the bottom sheet of said container and designed for energization by one type of current, rst heat source being adjacent to the cover sheet of said container and designed for energization by means of another type of current.

6. An incubator having inner and outer ccntainers, said inner container being adapted to support an infant therein, and individual heating elements for said inner container, the interior walls, bottom and cover of said inner container comprising metallic sheets providing rapid heat conduction and excellent heat reflecting surfaces, said metallic walls, bottom and cover of said inner container being in thermal engagement with one another, there being insulation on the exterior surfaces of said metallic walls and cover, said electrical heating elements for said inner and outer containers having different power capabilities, one of said heating elements `being adjacent said bottom wall and being designed for connection to house electrical power mains while the other heating element for said inner container is mounted upon the cover for said inner container and is designed for a direct current battery source of electrical energy, whereby the bottom, walls and cover are maintained at a relatively constant temperature to prevent loss by radiant deenergization of the infant within said inner container upon energization of either or both of the heating elements.

References Cited UNITED STATES PATENTS 2,093,648 9/1937 Rice. 2,470,721 5 1949 Pragel. 2,638,087 5/ 1953 Livsey. 2,641,248 6/ 1953 Armstrong. 3,338,233 8/1967 Groshola et al.

FOREIGN PATENTS 827,769 2/ 1960 Great Britain.

WILLIAM E. KAMM, Primary Examiner

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