Cover system for heating unit

A cover system for a heater unit includes a tray and a cap formed around the mouth of the tray. The tray holds a liquid medium that may be heated to various temperatures. The cap and the tray are coupled to prevent the passage of air and water. As a result, the cover system shields a non-sterilized heater unit from a sterile field in an operating room, thereby preserving the integrity of the sterile field.

TECHNICAL FIELD

The invention relates to devices used in a sterilized environment.

BACKGROUND

In an operating room, everything is categorized as sterile or non-sterile. The sterile items, which include the surgeon's gloved hands and the instruments that come in contact with the patient, have been made free of microorganisms according to aseptic techniques. To reduce the risk of infection, operating room personnel act to preserve a “sterile field,” i.e., the region in the operating room that is properly sterile. Operating room personnel are continually mindful of the sterile field, and conscientiously act to avoid contact between sterile and non-sterile items. By maintaining the integrity of the sterile field, the operating room personnel reduce the risk of transfer of microorganisms from non-sterile areas and items to the surgical wound.

In some circumstances, such as operations involving resorbable implants, it may be expedient to use a heating unit in the operating room. Resorbable implants, such as resorbable thin bone plates, often need to be shaped prior to fixation into the body. The steps involved in shaping these resorbable implants typically include submersing the resorbable implants into a heated water bath whereby the implants become malleable. Once malleable, the implants may be shaped into a desirable configuration.

The implants themselves are sterile, the water (or saline or other solution) in the bath is sterile, and the tray that holds the bath is sterile. The heating unit, however, typically includes electronic components and cannot be sterilized.

SUMMARY

The invention relates to a cover system that may be used to shield off a non-sterilized heater unit in a sterilized environment. The invention provides a cover system for a non-sterilized heater unit comprising a tray and a cap formed around a mouth of the tray. The tray holds a liquid medium that may be heated to various temperatures, and the cap is effective to prevent exposure of the non-sterilized heater unit to a sterilized environment. In one embodiment, the cover system is a single unit and is autoclavable, i.e., sterilizable in an autoclave.

The cover system is sized to fit over a heater unit, and the contours of the cover system may depend upon the contours of the heater unit being covered. In some embodiments of the invention, the cap is transparent or translucent, allowing instrumentation on the heater unit to be visible even when the heating unit is covered.

The cap and the tray may be coupled together by any of several techniques. They may, for example, be a single-piece construction, or they may be permanently joined by molding or another technique. The cap and the tray may also be coupled mechanically with a tight junction, and sealed with a sealant. With each of these techniques, the tray and the cap can be coupled to prevent the passage of air and water. A hermetic seal between the tray and the cap preserves the sterile field by physically separating a significant portion of the non-sterile heating unit from the sterile field. The hermetic seal further protects the heating unit in the event of spillage of water from the tray.

The cover system optionally includes a sterile drape. Moreover, in some embodiments of the invention, the cap includes a lip that can support a sterile drape. In that case, the drape effectively expands the cover system, thereby providing an added measure of isolation of the heater unit from the sterile field.

In one embodiment, the invention is directed to a cover system comprising a tray to hold a liquid to be heated by a heater unit. The tray includes a mouth. The cover system further includes a cap coupled to the tray, with the cap extending around the mouth of the tray and the cap being sized to cover at least a portion of the heater unit. The tray may be made of a material such as stainless steel, and the cap may be made of medical grade plastic. Several different materials may also be used to make up the cover system, however. The cover system may also include a drape, made of a material such as silicone.

In another embodiment, the invention is directed to a cover system comprising a tray and a cap coupled to the tray. The tray includes a mouth. The cap extends around the mouth and is sized to cover at least a portion of a heater unit. In accordance with the invention, the tray and the cap are coupled to prevent the passage of air and water.

In a further embodiment, the invention presents a system comprising a heater unit and a cover system sized to cover at least a portion of the heater unit. The cover system includes a tray and a cap coupled to the tray, and the tray and the cap are coupled to prevent the passage of air and water.

The invention may provide one or more advantages. In particular, the cover system allows the tray to be brought in contact with the heating element of the heater unit. As a result, the heater unit can transfer adequate heat to the tray without compromising the sterile field. It is unnecessary to have an intervening sterile guard between the tray and the heating element. The hermetic seal or tight junction between the tray and the cap prevents the passage of air and water, thereby preserving the sterile field and protecting the heating unit from spills.

The cover system may be easily sterilizable and reusable. The cover system can be easily placed over the heater unit and requires no complicated assembly. The addition of an optional drape can further isolate the heater unit from the sterile field.

DETAILED DESCRIPTION

Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same or similar reference numbers are used in the drawings and the description to refer to the same or like parts. It should be noted that the drawings are in simplified form and are not to precise scale. In reference to the disclosure herein, for purposes of convenience and clarity only, directional terms, such as, top, bottom, left, right, up, down, over, above, below, beneath, rear, and front, are used with respect to the accompanying drawings. Such directional terms should not be construed to limit the scope of the invention in any manner.

Although the disclosure herein refers to certain illustrated embodiments, it is to be understood that these embodiments are presented by way of example and not by way of limitation. The intent of the following detailed description, although discussing exemplary embodiments, is to be construed to cover all modifications, alternatives, and equivalents of the embodiments as may fall within the spirit and scope of the invention as defined by the appended claims.

An effective cover system for a heater unit, such as a surgical heater unit, is described. In a broad embodiment, the cover system comprises a tray and a cap formed around a mouth of a tray. Preferably, the cover system can snugly fit over a heater unit, so as to effectively cover the heater unit. A variety of heater units may be used in accordance with this invention. Generally, the heater unit has a heating surface on top of the heater unit to heat up the tray. In one embodiment, a heater unit used in accordance with this invention is capable of heating a liquid medium in the tray to a temperature of about 60 to about 70 degrees Celsius. U.S. Pat. No. 6,202,935 describes one exemplary heating unit, the disclosure of which is incorporated in its entirety herein by reference.

FIG. 1is a cross-sectional schematic view of a cover system20and a heater unit21. The cover system20is shown inFIG. 1comprising a tray22and a cap24. As will be described below, tray22and cap24may be constructed of different materials, but are coupled to form a single piece cover system. The tray22in the illustrated embodiment comprises a base29and a side wall30running up from the base29to hold a liquid medium26therein. The base29of the tray22may be of any shape, such as square, rectangular, oval or irregular. In one embodiment, the base29is rectangular shaped, and the side wall30extends between the four corners of the base29. An open end of the side wall30forms a mouth of the tray22. In another embodiment, the base29curves into the side walls30without corners, thereby forming the mouth. The mouth of tray22receives the sterile water or saline solution used in the heated water bath.

The cap24is formed around, or extends from, the mouth of the tray22so as to effectively cover the heater unit21. For example, from the mouth of the tray22, the cap24extends over the heater unit21and drops down the side of the heater unit21. In one embodiment, the cover system20snugly fits over the heater unit21, and the tray22rests against or in close proximity to a heating pad36or other heating element of the heater unit. The cap24need not contact heater unit21, however. As shown inFIG. 1, an air gap28may separate the cap24from the heater unit21. The air gap28provides some thermal insulation so that the cap24stays cool while the heating pad36heats tray22.

The tray22of the cover system20may be constructed from any material effective to transfer heat from the heater unit21to the liquid medium26, such as water, contained by the tray22. In one embodiment, the tray22is able to effectively transfer heat to the liquid medium26contained therein. For example, a tray22in accordance with the invention is capable of transferring adequate heat from the heater unit21below to heat a liquid medium26to about 60 through about 70 degrees Celsius in less than about 15 minutes, and preferably less than about 10 minutes. Preferably, the tray22does not rust and does not melt while transferring the required heat to the liquid medium26. In one embodiment, the tray22is stable to repeated sterilization processes, such as autoclaving and gamma radiation.

Furthermore, contaminants, such as microbes and the like, cannot permeate from one surface of the tray22to the other. Preferably, the tray22of the invention is autoclavable for sterilization. In one embodiment, the tray is constructed from stainless steel, the like, or mixtures thereof. In one embodiment, the tray22may have a dimension of 5⅛ inches (13.0 cm) by 6{fraction (9/16)} (16.7 cm) inches by 4 inches (10.1 cm). Preferably, the tray may hold about 1 to about 2 liters, and preferably about 1.5 liter, of the liquid medium26.

The cap24of the cover system20may be constructed from any material effective to seal off any contaminants on the surface of the heater unit21. Preferably, the cap24does not rust and does not melt when placed over the heater unit21in operation. In one embodiment, the cap24is stable to repeated sterilization processes, for example autoclaving and gamma radiation. In another embodiment, the cap21is constructed from the same material as that of the tray22, such as stainless steel. In one embodiment, the cap24is constructed from a material different from that of the tray, such as an autoclavable plastic. An example of an autoclavable plastic is Ultem plastics or resins, commercially available from GE Plastics of Pittsfield, Mass. In some embodiments, the autoclavable plastic is transparent or translucent, allowing medical personnel to be able to see instrumentation on the heater unit21, such as a temperature readout.

In one embodiment, the tray22and the cap24are molded as a single unit cover system20. In one embodiment, the cover system20may be constructed from deep molding a deep drawn stainless steel tank into a tinted (smoked) plastic cap. In another embodiment, the tray22and the cap24are removably attached together to form the cover system20. For example, the mouth of the tray22meets and attaches with the cap24, and a tight junction23is formed therebetween. By tight junction, it is meant that a contaminant cannot pass through the interface where the tray22and the cap24meet. The use of any known means of attachment between the tray22and cap24is possible, such as an attachment through use of an adhesive, or riveting, clamping, snapping, bolting or latching. A sealant, such as silicone seal or a gasket, may be employed to create or improve a tight junction23between the tray22and the cap24. In particular, the sealant may be deployed between the tray22and the cap24to create or to assure an airtight and watertight hermetic seal.

Whether formed as single piece or joined with a tight junction, the tray22and cap24are coupled by a hermetic seal that prevents the passage of air and water. The hermetic seal serves at least two functions. First, the hermetic seal preserves the sterile field by physically separating the non-sterile heating unit21from the sterile field. Second, the hermetic seal protects the heating unit21. In the event water from tray22spills, water will not penetrate the hermetic seal and get into the heating unit21, and possibly causing damage to the electronic components of the heating unit21. In a preferred embodiment, the cover system20comprising the tray and the cap is sterilized prior to use.

Referring to the cross-sectional schematic view shown inFIG. 2, the cap24preferably comprises a lip31surrounding the mouth of the cap24. In other words, the cap includes an outer perimeter that extends around the heating unit21, and the outer perimeter includes the lip31. A drape27can be attached to the lip31of the cap24by various means, such as hook and loop fasteners including Velcro®. In such an embodiment, the lip31may be reduced or altered in size or shape, or eliminated. In a preferred embodiment of the invention, the drape27comprises an opening which is shaped to approximate the inner circumference of the lip31, so that the opening of the drape27can fit around the cap24and slide down to rest on the lip31. A circumference of the outer edge (measured in a radial direction) of the lip31is preferably slightly greater than a circumference of the opening of the drape27, so that the drape27is caught on the lip31to prevent the drape27from sliding further down and off of the lip. In one embodiment, the drape27is effective to cover the area surrounding the heater unit21.

FIG. 3is a perspective view of an embodiment of the invention. A cover system40comprises a tray42and a cap44. The cap44is formed around the mouth of the tray42, and the junction46between the tray42and the cap44comprises a hermetic seal that prevents the passage of air and water.

The cover system40is sized to fit over a heater unit48. In particular, the cover system40is dimensioned so that the tray42rests in a well50, and the base52of the tray42rests against or is in close proximity to a heating pad54of the heater unit48. In addition, the cap44follows the general contours of the heater unit48. The cap44may be sized to touch the heater unit48, or may be sized to be separated from the heater unit48by an air gap when the tray42rests in the well50.

FIG. 4is a is a perspective view of the embodiment of the invention shown inFIG. 3, with the cover system40covering the heater unit48. In the embodiment shown inFIG. 4, the cap44is transparent or translucent. Accordingly, instrumentation on the heater unit48, such as a temperature readout56, is visible through the cap44when the cover system40covers the heater unit48.

The embodiment of the cover system40shown inFIGS. 3 and 4provides some isolation of the heating unit48from the sterile field. The hermetic seal46between the tray42and the cap44preserves the sterile field by physically separating a significant portion of the non-sterile heating unit48from the sterile field. The hermetic seal46further protects the heating unit48in the event water from the tray42spills.

As shown inFIGS. 3 and 4, the cap44comprises a lip58, which can support a drape as shown below. As shown inFIG. 4, the lip58does not hinder access to an on-off switch60or a power cord62of the heater unit48when the cover system40covers the heater unit48. The lip58does not isolate the on-off switch60or the power cord62from the sterile field, however. When the drape is in place as shown inFIG. 6below, the on-off switch60and the power cord62are isolated from the sterile field.

FIG. 5is a perspective view of the cover system40and the heater unit48shown inFIGS. 3 and 4, along with a drape70. The drape70includes an opening72that is shaped to approximate the inner circumference of the lip58, so that the opening72of the drape70can fit around the cap44and rest on the lip58. The drape70is flexible so that it can drape over nearby equipment. The drape70may also be transparent or translucent, so that the covered equipment, or parts thereof, can be easily seen.

The drape70is made of sterilizable material. A variety of materials may be used for the drape70. In one embodiment, the drape70comprises a thin, textured silicone membrane. The drape70may be sterilized in advance, and brought into the operating room in a sterile container. The drape70may be re-sterilized or discarded after use.

The drape70may be of any dimension. As shown inFIG. 5, the drape70can extend outward from the cap44, thereby covering heater unit48to a greater degree. In one embodiment, the drape70extends about one foot to two feet (30 to 61 cm) radially outward from the opening72, but the dimensions of the drape70may vary. AlthoughFIG. 5shows the drape70as being substantially rectangular with the opening72in the approximate center of the drape70, the drape70may be any shape and the opening72may be located anywhere.

FIG. 6is a perspective view showing an exemplary deployment of the invention. In an operating room, the heater unit48may be placed on a “Mayo stand”74, i.e., heater unit48may be supported on a tabletop76of the stand74. The cover system40covers the heating unit48and at least partially isolates the heating unit48from the sterile field. The drape70is deployed to cover the heater unit48and at least portions of the power cord62and the stand74. In the embodiment shown inFIG. 6, the drape70extends about one foot (30 cm) below the tabletop76of the stand74. When cover system40, heater unit48and drape70are deployed as shown inFIG. 6, a sterile person in the operating room is less likely to become non-sterile by inadvertently bumping stand74.

In this configuration, the drape70isolates the on-off switch60from the sterile field. The drape70does not prevent operating room personnel from having access to the on-off switch60, however. Non-sterile personnel can access the on-off switch60by reaching under the drape70without invading the sterile field. Sterile personnel can access the on-off switch60by depressing the on-off switch60through drape70.

The cover system of the invention may be shaped as to accommodate for the various features of the heater unit it is covering. For example,FIG. 7shows a cover system120sized and configured for a different model of heating unit122. In the embodiment of the cover system shown inFIG. 7, the cap124includes a cut out135to provide accessibility to an on/off switch134on the heater unit122. The cut out135may be patched over by a soft cover140to allow for manipulation of the on/off switch134through the soft cover140. Preferably, the soft cover140is a plastic, and more preferably a transparent plastic. A similar cut out142may be available to allow access for other items, such as the power cord144of the heater unit122. Other cut outs may be available for viewing of a temperature gauge or other instrument on the heater122, for example. A drape can be added to optionally cover any cut outs and corresponding elements of heater unit122that protrude through such cut outs.

The invention may provide one or more advantages. In particular, the cover system allows the tray to be brought in contact with the heating element of the heater unit. As a result, the heater unit can transfer adequate heat to the tray without compromising the sterile field. The invention can avoid the need for an intervening sterile guard between the tray and the heating element. The hermetic seal or tight junction between the tray and the cap prevents the passage of air and water, thereby preserving the sterile field and protecting the heating unit from spills.

The cover system may be easily sterilizable and reusable. The cover system may be easily placed over the heater unit and typically requires no complicated assembly. The addition of an optional drape can further isolate the heater unit from the sterile field.

While this invention has been described with respect to various specific examples and embodiments, it is to be understood that the invention is not limited thereto and that it can be variously practiced. A cover system may be customized to the conformation of a particular kind of heater unit, for example, so the invention is not limited to the specific conformations shown in the figures.

Because a cover system may be dimensioned for a particular kind of heater unit, the cover system may include one or more coupling elements that temporarily couple the cover system to the heater unit. Snaps, hasps, springs, ribs, notches, grooves and clasps are examples of coupling elements. A cover system may include leaf springs, for example, that mate to grooves on the heater unit, or vice versa. With coupling elements such as these, the cover system can snap into place in the heater unit. Not only do coupling elements help secure the cover system to the heater, the coupling elements may also provide audible or tactile feedback indicating to a user that the cover system is properly in place.

Furthermore, the cover system need not be formed from a tray and cap of different materials, but may be formed as a single-piece construction. The drape may be included as an integral part of the cover system, or may be omitted completely.

The cover system need not include a lip to support a drape. As shown inFIGS. 3-7, a cover system may include tapered sides, and the opening of the drape may be sized to slide part way down the sides.

The invention need not be constructed with the specific materials described herein. For example the tray need not be made of stainless steel, but may be made of another metal, or may be made of plastic or another heat-conductive material. The cap need not be formed from a plastic or polymer, but may be formed from metal or any other material. These and other embodiments are within the scope of the following claims.