The present invention relates to an infant care apparatus and, more particularly, to an infant incubator having a uniform and symmetrical flow pattern to provide an even distribution of heat within the infant compartment.
There are, of course, many infant incubators available today for the caring of infants and to provide heat and, generally, humidity to that infant to aid in its wellbeing. In general, such incubators comprise an infant platform that is affixed to a base so as to locate the infant platform at a convenient height for the caregiver to view and attend to the infant. Within the infant platform, there is a flat, planar surface that underlies and supports the infant. A plurality of transparent sides generally extend upwardly from the infant platform to surround the infant and create the isolated infant compartment within which the infant is positioned. As indicated, the infant compartment allows the creation of a controlled environment and provides heat and humidity to the infant to aid in its growth and development.
In most incubators, the infant is heated by means of a heated flow of air that is introduced into the infant compartment to warm the infant and there is a recirculation of air from the infant compartment to be reintroduced to the heating system to be re-circulated back into the infant compartment. Thus, there is a heating and air moving compartment, normally positioned within the infant platform and located underneath the flat, planar surface on which the infant lies so as to be close to the infant compartment in order to conserve heat to the infant. That heating and air moving compartment contains the necessary components to heat and force the air into the infant compartment and conventionally comprise an electric heater and a motor powered fan to provide that heated air to the infant compartment.
The actual introduction of the heated air and the removal of air from the infant compartment also varies among incubators, however, it is preferable that the air flow within the infant compartment be uniform so as to create a uniform, even heat distribution within that compartment. As used hereinafter, since the base of the infant compartment is generally rectangular, there is a long dimension that will be referred to as the longitudinal side of the infant compartment or incubator and a shorter dimension that will be referred to as the end of the infant compartment or incubator. In use, the infant is normally placed parallel to the longitudinal sides of the infant compartment and there are access doors along those sides or side, so that access can be had to the infant by the caregiver.
In various incubators there are certainly differing systems to introduce the heated air into the infant compartment. For example, in U.S. Pat. No. 5,730,355 of Lessard et al, there is a flow pattern that introduces the heated air into an infant compartment through openings along the elongated sides of the infant compartment and to cause the air to exit from the infant compartment along only one of the ends of the infant compartment. Accordingly, the air flow is not uniform as all of the air introduced is removed along one of the ends and would tend to create a cooler area at the upper end of the infant compartment where there is no opening for the air to exit the infant compartment. The non-uniformity can also create a cooler area on the inside walls of the incubator.
Further, in Beer et al, U.S. Pat. No. 4,617,912, there is an air flow pattern wherein the heated air enters the infant compartment along both of the sides of the incubator and exits the infant compartment along the ends of the infant compartment. While more uniform, it is noted that the air directly enters the infant compartment at the bottom of the compartment and does not pass through a double walled door to enter the infant compartment at the top thereof. Thus, the inflow of warm air is subject to partial blockages or diversions that may be caused by a blanket or other material within the infant compartment that can upset the uniformity of the warm air flow at the sides of the incubator where such items may be present.
As an example of means to avoid partial blockages of side openings of the warm air into an infant compartment, double walls are used in some infant incubators, such as in Koch et al U.S. Pat. No. 4,936,824, where the inner walls of the infant compartment are actually heated by the flow of the heated air to raise the temperature of those walls in order to reduce the radiant energy loss of the infant to such walls. When such double walls are used, therefore, it is desirable that the wall temperature be fairly uniform across the inner surface of the walls. Again, therefore, a uniform, symmetrical flow pattern would be advantageous. As is noted in Koch et al, while blockage of the inlet flow paths are eliminated, there is a distribution pattern of the heated air that follows the inlet passage within the hood from front to back of the infant compartment where the air is substantially contained within the walls of the hood. Basically, in the Koch et al construction, there is an inlet along one longitudinal side and one outlet along the opposite longitudinal side with the heated air contained generally within a passageway formed between a double walled hood.
Accordingly, it would be desirable to provide a heating system that introduces the heated air into the infant compartment in a uniform pattern so that the areas within the infant compartment are generally at the same temperature and with the use of air passages through double walls of the infant compartment. As such, the areas of the double walls are at a more uniform temperature to lower the heat loss of the infant. In addition, it would be further advantageous to be able to provide a uniform flow pattern with a minimum of components in convective heating system by means of a heating and air moving compartment that is efficient and yet which provides the heating and air movement along the paths desired by utilizing large, molded components.
Accordingly, the present invention relates to an infant incubator that has a base and a frame extending upwardly from the base and which has an infant platform extending outwardly, preferably in cantilever manner, from the frame. The infant platform has a flat, planar, generally rectangular surface to provide a support for positioning the infant and has longitudinal sides and ends. An infant compartment is formed about the infant resting on the flat, planar surface by means of peripheral walls extending upwardly from said longitudinal sides and the ends and a cover that encloses and retains the infant within a controlled environment.
A convective heating system is used to force a flow of heated air into the infant compartment and to return air from that infant compartment. In the preferred embodiment, the components of the convective heating system are located in a heating and air moving compartment that is located within the infant platform just beneath the flat, planar surface on which the infant rests to minimize the loss of heat between the convective heating system and the infant compartment. Those components of the convective heating system include a fan, a motor to power the fan, a heater, and the various ducting and passageways to direct the air into and out of the infant compartment.
In that heating and air moving compartment, the convective heating system is readily constructed and assembled by a minimum, of large molded plastic components including a one-piece molded chassis and a molded upper pan that fits over the chassis and forms therebetween a lower chamber and an upper chamber.
In the preferred system, elongated inlets are formed along the opposite ends of the infant compartment and allow air to pass from the infant compartment through those elongated inlets and which then communicate with the lower chamber. In similar fashion, the upper chamber communicates with the infant compartment through elongated outlets that are formed along the longitudinal opposite sides of the infant compartment. A fan, powered by a motor, is located intermediate the upper and the lower chambers and serves to force the air from the lower chamber to the upper chamber and thus, to move the air from the infant compartment via the elongated inlets to return to the infant compartment t through the elongated outlets. In the preferred embodiment, a heater is located in the lower chamber to heat the air passing through that chamber.
In the system, therefore, the air thus moves from the infant compartment along the opposite ends and returns to the infant compartment along the opposite longitudinal sides of the infant compartment. Thus, with the use of only two molded plastic components, the system efficiently heats and delivers the air as desired with a minimum of components and thus is readily assembled.
By means of the present invention, the heated air from the convective heating system is introduced into the infant compartment along both of the longitudinal sides of the infant compartment and the return air leaves the infant compartment along both of the ends of the infant compartment via openings along those respective longitudinal sides and ends of the infant platform.
In the present invention, the side longitudinal walls of the infant incubator are double walls, that is, they comprise an inner and an outer wall spaced apart so as to form a passageway between the inner and outer walls to allow the heated air to pass through the longitudinal walls such that the heated air is introduced into the infant compartment at or near the upper regions of the infant compartment. In such manner, the side longitudinal walls are heated much in the same manner as in the Koch et al U.S. Pat. No. 4,936,824 to resist radiant losses from the infant through those walls.
According, the flow of heated and return air is basically symmetrical and uniform through the infant compartment. The heated air enters the infant compartment along both of the longitudinal sides of the flat, planar surface and leaves the infant compartment through both of the ends of the infant compartment and therefore the flow pattern, as well as the heat distribution throughout the infant compartment, is more uniform.
These and other features and advantages of the present invention will become more readily apparent during the following detailed description taken in conjunction with the drawings herein.