Incubator

Abstract

An incubator is described that comprises an insulated chamber in which heating of a culture media takes place by conduction and the incubator is designed to prevent overheating of the culture media and provide uniform temperature control. The incubator has a broad field of application and is particularly adapted because of its compactness for use in a physician's office.

Description

This invention relates to an incubator unit.

Incubators are in use today for a variety of purposes including hatching eggs, growing bacteria in a suitable media, etc. Many of the incubators now available have a variety of shortcomings including: non-uniform temperatures throughout the incubator which makes it difficult to determine accurately whether the culture is being maintained at the critical temperature level; non-uniform heating of the culture media; overheating of the culture media; poor design and construction which makes it difficult to maintain a specific gas atmosphere tension (e.g. CO.sub.2 tension) required for the bacterial growth; and poor visibility of the culture media from outside of the incubator thereby hindering the accurate determination of the presence or absence of bacterial growth without opening the incubator.

Accordingly, the present invention provides for an incubator that overcomes the deficiencies of prior art incubators.

One object of the present invention is to provide an incubator in which the culture media is heated by conduction rather than convection.

Another object of the present invention is to provide an incubator that provides substantially uniform heating of the culture media.

A still further object of the present invention is to provide an incubator in which overheating of the culture media is avoided.

An additional object of the present invention is to provide an incubator that is particularly adapted for growth of bacteria requiring a CO.sub.2 atmosphere such as used in testing for gonorrhea.

Other objects and advantages of the present invention will be apparent from the following detailed description and accompanying drawings which set forth the principles of the invention in which

FIG. 1 shows a front elevation in section of the incubator of the present invention; and

FIG. 2 is a detailed cross-sectional view taken along the line 2--2 of FIG. 1.

Referring to the drawings for a more detailed description of the structure and operation of the incubator of the present invention, FIG. 1 shows an incubator 10 comprising flat vertical side walls 11, a flat bottom wall 12 and a flat removable cover 13 which is at least partially transparent and forms with walls 11 and 12, chamber 14. Since it is essential that the incubator be insulated to maintain a selected incubation temperature, side walls 11 and bottom wall 12 are constructed of suitable insulation material such as, for example, a foamed polyurethane. Transparent top cover 13 may be constructed of any suitable transparent material (e.g. glass, a rigid plastic such as "Plexiglass" etc.) to permit clear visibility of the culture media to determine the presence of any bacterial growth without opening the incubator. Cover 13 has secured to it, by adhesive or other suitable means, lip 15 constructed, for example, of a foamed polyurethane which seals the chamber 14 when cover 13 is in place as shown in FIG. 1. This provides a tight fit that will permit the maintenance of a specific gas atmosphere tension (e.g. CO.sub.2 atmosphere) in the chamber 14 over the desired time period.

Referring now to FIG. 2, the insulated chamber 14 is provided with a two piece platform 16 designed to permit rapid assembly of the incubator and its heating unit and to fit firmly within the four corners of chamber 14. Platform 16 comprises one section having oppositely slanted surface portions 17 and 18, flat horizontal surface area 19 joined with slanted surface 18 and vertical leg members 20 and 21 extending to the inside face of bottom wall 12, with leg member 21 contacting the inside face of one of vertical side walls 11. Slanted surface portion 18 and flat surface area 19 form a bed for a thermometer 23 placed in a horizontal position in insulated chamber 14, the thermometer being secured to flat surface area 19 by conventional means such as a bracket 22 or the like. Having thermometer 23 in a horizontal position permits easy sighting of the incubator temperature through transparent cover 13. The second section of platform 16 comprises a flat horizontal surface area 24, a slanted surface portion 25 which forms with adjacent slanted surface 17 a bed for receiving and retaining one or more culture containers 26 in an inclined position from the horizontal, and leg members 27 and 28 extending to the inside face of bottom wall 12 with leg member 27 bearing against leg member 20 of the other section of platform 16. Horizontal surface area 24 is provided with an opening for receiving and holding in a vertical position container 29 (e.g. a glass vial) in which a gas releasing agent 30, such as a CO.sub.2 tablet, is placed together with water or other suitable liquid. Platform 16 is preferably constructed of a light material that is a good heat conductor, such as aluminum, so that heating of the culture in container 26 is by conduction through slanted surface 17 as will be explained hereafter in connection with the design of the heating unit for incubator 10.

As shown in FIG. 2, the heating unit comprises a heating element 31 such as a resistor, a thermostat 32 and a heat conducting plate 33 each of which is located within insulated chamber 14 and under platform 16. A pilot light 34 is provided on horizontal surface area 19 which goes on when the temperature is below the desired level and cuts off when the incubator temperature reaches the desired level and a heat control knob 35 is provided on the exterior of incubator 10 for regulating the incubator temperature. The control knob 35 is marked with an indicator to permit selection of the desired temperature that is calibrated on a scale on the outside face of the side wall 11 opposite the heat control knob. Heat conducting plate 33 is designed so that at its one end it is wrapped around and in contact with heating element 31 and at its other end it is in contact with slanted surface 17 constructed of a heat conductive material, as previously indicated. Intermediate its ends, heating plate 33 has a vertical section 36 that is secured to a face of thermostat 32 by conventional means such as bolt 37 which also secures thermostat 32 to vertical leg 21. Therefore thermostat 32, heat conducting plate 33 and one section of platform 16 are bolted together as a unit.

The design of platform 16 and the heating unit arrangement described in the preceding paragraph permits for accurate and uniform heating of container 26 in that a larger surface area of the solid culture media in container 26 is exposed to heating by conduction because such container is in an inclined position rather than in the conventional vertical position. Overheating of the culture media is avoided through a temperature control that will maintain an accuracy of plus or minus one half a degree between 95.degree. to 105.degree. F. In operation the heat generated from heating element 31 is conducted along heat conducting plate 33 and transferred by conduction to slanted surface portions 17 and 18 and horizontal surface 19 through the contact between heat conducting plate 33 and slanted heat conductive surface 17. Overheating of the culture media is avoided because heat from the heating element 31 must pass by thermostat 32 along heat conducting plate 33 before it reaches slanted surface portion 17. This permits an accurate control of the temperature at slanted surface 17 inasmuch as this surface cannot become heated to a temperature above the preselected level because thermostat 32 cuts out when the desired temperature is reached at the thermostat thereby preventing excess heat transfer along heat conducting plate 33 to slanted surface 17.

In operation the heating element can be plugged into any 110 volt AC outlet and because of its compactness carried from one point to another with no effort. It is ideal for use in a doctor's office, a hospital, laboratory or research facility. Another advantage of the incubator of the present invention is its flexibility of use. For example, horizontal surface 24 may be provided with a plurality of openings for receiving and retaining in a vertical position vials containing a liquid culture media where such a culture media is required for a particular test such as the detection of trichomonas.

The incubator of the present invention has been found to be ideal for use in detection of neisseria gonorrhea where careful temperature control and uniform heating of a solid culture media is important for accurate results.

Other modifications and variations will be apparent to those skilled in the art and it is accordingly intended that the scope of the invention not be limited to those embodiments particularly illustrated or suggested but that the scope of the invention be defined by reference to the appended claims.

Claims

We claim:

1. An incubator for warming a culture container to a desired temperature comprising an insulated housing defining a chamber, culture container support means of a heat-conductive material located within said chamber, said support means shaped to hold a culture container thereon in a position inclined with respect to the vertical so that a fluid culture medium in the container will be disposed therein and said support means will contact both the bottom wall and an inclined surface of the container resting on said support to conduct heat to the container to heat the medium contained therein, transparent material comprising a portion of said chamber to permit viewing of a culture container within the chamber, electrically operated heating means, heat conducting means between said heating means and said support means and in physical contact with both said heating means and said support means to conduct heat from said heating means to said support means to heat said support means, and heat regulating means electrically connected to said heating means and in heat conductive relationship with said support means for sensing the temperature of said support means and for controlling the operation of said heating means to maintain said predetermined temperature.

2. An incubator according to claim 1 wherein said heating means and said container support means are in contact with said heat conducting means at opposed ends of said heat conducting means.

3. An incubator according to claim 2 wherein said heat regulating means is in contact with said support means at a position intermediate the ends of said heat conducting means.

4. An incubator according to claim 3 wherein said heat regulating means comprises a thermostat.

5. An incubator according to claim 1 which includes means for holding a gas releasing agent within said insulated chamber.

6. An incubator according to claim 3 further comprising means for retaining a heat measuring device in a substantially horizontal position in said insulated chamber at a location viewable through said transparent portion.

7. An incubator according to claim 1 further comprising means for holding another culture media container in a substantially vertical position.