SURGICAL CAST VENTING MEANS
United States Patent 3762406
A cast vent has a conduit having an enlarged head. An inner positioner inserts in the opposite end. It has a cap, for the end of the conduit, and a flange. In use the vent is mounted in the wall of a surgical cast during make up with the head of the conduit positioned inside the cast. The flange is mounted on the outer end of the conduit, which is covered by the cap. The cap is replaced by a conduit flange when the cast is finished to provide communication from the inside of the cast to the atmosphere.
US Patent References:
ORTHOPEDIC CAST
Thomas - April 1972 - 3656477
Cast ventilating arrangement
Baxter - January 1964 - 3116731
Thermostatic ventilation button for orthopedic devices
Chester - September 1961 - 2998921
ORTHOPEDIC CAST
Thomas - April 1972 - 3656477
Cast ventilating arrangement
Baxter - January 1964 - 3116731
Thermostatic ventilation button for orthopedic devices
Chester - September 1961 - 2998921
Application Number:
05/209704
Publication Date:
10/02/1973
Filing Date:
12/20/1971
View Patent Images:
Export Citation:
Primary Class:
International Classes:
A61F13/04; A61F5/04
Field of Search:
128/91R,91A,90,89R,89A 236/49
Primary Examiner:
Gaudet, Richard A.
Assistant Examiner:
Yasko J.
Claims:
I claim
1. A vent means mounted within a wall of a surgical cast during make up comprising a conduit member having a passageway therethrough and an enlarged head on one end thereof, a hollow positioner member insertable inside the opposite end portion of said conduit member and connected thereby by means to engage said positioner member with said conduit member, and an end cover member including said positioner member enclosed therein and connected to said opposite end portion of said conduit member by means to engage said cover member with said conduit member.
2. The vent means of claim 1, wherein, said conduit member has said head extending radially therefrom, a perforate shield means is attached to said head of said conduit member covering said passageway therein, and said positioner member includes a flange on one end thereof adapted to engage the interior of said cover member.
3. The vent means of claim 2, wherein, said conduit member includes first threads on said passageway and second threads on the outside thereof, said means to engage said positioner member with said conduit member includes third threads on the outside of said positioner member engaging said first threads, and said cover member is cylindrical and said means to engage said cover member with said conduit member includes fourth threads positioned on the interior of said cover member engaging said second threads.
4. The vent means of claim 3, wherein, said perforate shield means comprises a perforate plug insertable in the end portion of said conduit passageway, and a shield member attached to said enlarged head and enclosing said perforate plug within said conduit passageway, said shield member including a structure defining a mesh covering, and said conical end cover has a conical end portion.
5. A vent means mounted within a wall of a surgical cast during make up comprising a conduit member having a passageway therethrough and an enlarged head on one end thereof, a hollow positioner member insertable inside the opposite end portion of said conduit member and connected thereto by means to engage said positioner member with said conduit member, and a hollow flange member attached to the opposite end portion of said conduit member.
6. The vent means of claim 5, wherein, said conduit member has said head extending radially therefrom, a perforate shield means is attached to said head of said conduit member covering said passageway therein, said positioner member has a flange on one end thereof adapted to engage the interior of said conduit end cover member, and said flange member is a conduit segment whose interior includes first threads and an end which is conically divergent.
7. The vent means of claim 6, wherein, said conduit member includes second threads on said passageway and third threads on the outside thereof, said means to engage said positioner member with said conduit member includes fourth threads on the outside of said positioner member engaging said second threads, and said first threads engage said third threads.
8. The vent means of claim 7, wherein, said perforate shield means comprises a perforate plug insertable in the end portion of said conduit passageway, and a shield member attached to said enlarged head and enclosing said perforate plug within said conduit passageway, said shield member including a structure defining a mesh covering.
9. A method for venting the walls of a surgical cast during make up comprising:
10. The method of claim 9 wherein a hollow flange member is substituted for said cover member.
11. The method of claim 9 additionally including attaching a perforate shield on said enlarged head.
1. A vent means mounted within a wall of a surgical cast during make up comprising a conduit member having a passageway therethrough and an enlarged head on one end thereof, a hollow positioner member insertable inside the opposite end portion of said conduit member and connected thereby by means to engage said positioner member with said conduit member, and an end cover member including said positioner member enclosed therein and connected to said opposite end portion of said conduit member by means to engage said cover member with said conduit member.
2. The vent means of claim 1, wherein, said conduit member has said head extending radially therefrom, a perforate shield means is attached to said head of said conduit member covering said passageway therein, and said positioner member includes a flange on one end thereof adapted to engage the interior of said cover member.
3. The vent means of claim 2, wherein, said conduit member includes first threads on said passageway and second threads on the outside thereof, said means to engage said positioner member with said conduit member includes third threads on the outside of said positioner member engaging said first threads, and said cover member is cylindrical and said means to engage said cover member with said conduit member includes fourth threads positioned on the interior of said cover member engaging said second threads.
4. The vent means of claim 3, wherein, said perforate shield means comprises a perforate plug insertable in the end portion of said conduit passageway, and a shield member attached to said enlarged head and enclosing said perforate plug within said conduit passageway, said shield member including a structure defining a mesh covering, and said conical end cover has a conical end portion.
5. A vent means mounted within a wall of a surgical cast during make up comprising a conduit member having a passageway therethrough and an enlarged head on one end thereof, a hollow positioner member insertable inside the opposite end portion of said conduit member and connected thereto by means to engage said positioner member with said conduit member, and a hollow flange member attached to the opposite end portion of said conduit member.
6. The vent means of claim 5, wherein, said conduit member has said head extending radially therefrom, a perforate shield means is attached to said head of said conduit member covering said passageway therein, said positioner member has a flange on one end thereof adapted to engage the interior of said conduit end cover member, and said flange member is a conduit segment whose interior includes first threads and an end which is conically divergent.
7. The vent means of claim 6, wherein, said conduit member includes second threads on said passageway and third threads on the outside thereof, said means to engage said positioner member with said conduit member includes fourth threads on the outside of said positioner member engaging said second threads, and said first threads engage said third threads.
8. The vent means of claim 7, wherein, said perforate shield means comprises a perforate plug insertable in the end portion of said conduit passageway, and a shield member attached to said enlarged head and enclosing said perforate plug within said conduit passageway, said shield member including a structure defining a mesh covering.
9. A method for venting the walls of a surgical cast during make up comprising:
10. The method of claim 9 wherein a hollow flange member is substituted for said cover member.
11. The method of claim 9 additionally including attaching a perforate shield on said enlarged head.
Description:
Numerous types of cast venting devices are known in the prior art operable to vent a cast providing for the passage of air from the inside of a surgical cast to the atmosphere. However, these prior art devices are usually constructed of a resilient material and constructed in such a form that they can only be used in one cast installation, then they must be totally discarded along with the cast when it is no longer needed. Additionally, some of the prior art devices are constructed of conduits with a tapering cross-section that is larger near the body and having a small opening to the atmosphere; this design substantially restricts airflow through the vent. Generally the prior art devices depend upon the adhesion between the vent structure itself and the plaster or other cast material to hold them in place; this design works fine as a theory, but as a practical matter the vent structure will dislodge from the cast and move inward pressing against the body of the cast wearer causing pouting of the flesh into the vent thereby becoming very uncomfortable.
In one preferred specific embodiment of this invention, the vent structure includes a conduit to be mounted in a cast with a positioner insertable inside the outer end of the conduit having an end cover used in installing the vent, and having a flanged member to be connected to the conduit on the outside of the cast. The conduit has an enlarged head on one end to be placed in the cast's interior cavity with the cylindrical portion of the conduit extending outward to the cast. The positioner is engagable in the interior passageway of the conduit and contacts the conduit end cover. The conduit end cover is used for installing the vent in a cast and it is removed after the cast is made up. The conduit flange replaces the conduit end cover when the vent is in place in the cast in order to provide open fluid communication between the interior of the cast and the atmosphere. A shield is provided on the surface of the conduit head to prevent pouting of the flesh inside the cast and to provide a separation between the material of the conduit head and the person's body. The conduit, positioner and conduit flange member are preferably constructed of a non-allergenic and corrosive resistant material which is inexpensive and can be disposed of along with the cast when it is no longer needed. The conduit end cover is used only in installation of the vent structure and is constructed of durable material so it can be re-used to install other vents.
One object of this invention is to provide a surgical cast venting means overcoming the aforementioned disadvantages of the prior art devices.
Still, one other object of this invention is to provide a surgical cast venting means having a conduit apparatus to provide fluid communication between the inner cavity of a cast and the atmosphere which has a divergent outer portion to enhance airflow and a shield on the inner surface thereof to prevent pouting of the wearer's flesh inside of the cast against the vent.
Still another object of this invention is to provide a surgical cast venting means which has a conduit member that can be covered during the installation of the vent in a cast and uncovered when the vent is installed in the finished cast.
Yet, one additional object of this invention is to provide a surgical cast venting means which has a conduit cover which can be re-used to install the disposable conduits of the invention in surgical casts.
Various other objects, advantages, and features of the invention will become apparent to those skilled in the art from the following discussion, taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a side elevation view of a cast on a person's foot having a plurality of vent structures of the invention installed therein, and having a viewing window installed in the cast;
FIG. 2 is a cross-sectional view of a cast having three of the vent structures installed therein, one structure with the conduit end cover in place, another structure with the conduit end cover removed, and a third structure with the conduit flange member in place thereon;
FIG. 3 is a perspective view of the vent structure in exploded form and showing the conduit end cover member;
FIG. 4 is an exploded elevation view in cross-section of the vent structure with the pointed conduit end cover member; and
FIG. 5 is a cross-sectional elevation view of the conduit outer end flange member.
The following is a discussion and description of preferred specific embodiments of the surgical cast venting means of this invention, such being made with reference to the drawings, whereupon the same reference numerals are used to indicate the same or similar parts and/or structure. It is to be understood that such discussion and description is not to unduly limit the scope of the invention.
Referring to the drawing in detail and in particular to FIG. 1, showing a cast 10 on a foot 12 with a plurality of vent structures 14 of this invention mounted therein. The components of the vent structure 14 are shown in FIGS. 3, 4 and 5; the vent structure 14 includes a conduit assembly 18, an inner conduit positioner member 20, an end cover member 22, and a conical flanged end member 24. The conduit assembly 18 includes the conduit itself and a shield assembly 26 on its enlarged end. As can be seen clearly in FIG. 4 the conduit assembly 18 has an elongated shank portion 28 with a radially extended head portion 30 at one end thereof, and a passageway 32 extending through the shank portion 28. The shank portion 28 of the conduit assembly 18 is threaded on the inner surface 34 of the passageway 32 and on its outer surface 36. The shield assembly 26 is attached to the conduit head 30 and includes a perforated plug member 38 and an overlying mesh member 40. The plug 38 preferably has a plurality of apertures through it to provide for relatively open fluid communication. When the plug 38 is in place in the conduit assembly 18, it rests in the mouth of the passageway 32. The mesh member 40 is preferably a relatively open weave cloth like material attached to the end surface 42 of the conduit head 30 and adapted to hold the plug 38 in its relative position at the mouth of the passageway 32. The shield assembly 26 prevents pouting of the flesh, a condition whereby the skin of a person wearing a cast would be pushed outward into the passageway 32 if the shield assembly was not in place. Pouting is desirable to be avoided because it produces skin irritation followed by itching and general discomfort for the wearer of the cast.
The inner conduit member 20 has a shank portion 42 with a passageway 44 through it. The shank 42 is threaded on its outer surface 46 and has a radially extending flange 48 at one end thereof. The threaded shank portion 46 is adapted to engage the threaded passageway 32 in the conduit assembly 18. The flange 48 is sized sufficiently large so that it will prevent the inner conduit member 20 from passing completely into the threaded passageway 32. The inner conduit positioner member 20 is used as a lengthening and positioning device in the installation of the vent 14 as will be described hereinafter.
The end cover member 22 is basically a cap-like structure threaded to engage the outward extending end of the conduit assembly 18 and pointed on its outer end. Specifically, the conduit end cover member 22 has a sidewall 50 integral with the pointed end 52 with the sidewall threaded on its interior 54 to engage the outer threaded portion 36 of the conduit assembly shank 28. A recessed area 56 is provided inside the point end portion of the end cover to receive the flange portion 48 of the inner conduit 20. The pointed end cover 22 is re-used again and again in installing the vents in a cast. For the reasons of re-usability the end cover 22 is preferably constructed of a rigid and durable material, for example, surgical steel or the like.
The conically flanged conduit end member 24 is shown in detail in FIG. 5. It includes a sidewall 60 threaded on its interior surface 62 and having an integral and conically outwardly flanged portion 64. The conically flanged conduit end 24 replaces the pointed end cover 22 once the vent structure 14 is in place in a cast. The conically flanged conduit end 24 is screwed onto the shank portion 28 of the conduit 18 once the conduit assembly 18 has been set in a cast. The threaded portion 62 of the conically flanged conduit is adapted to be engaged with the outer threaded portion 36 of the conduit assembly 18. The conically flanged end 24 is preferably constructed of the same type of material as the conduit assembly 18 and the inner conduit member 20 for similar reasons.
The process of installing the vent structure 14 in a cast is generally illustrated in FIG. 2 wherein the vent structure 14 is shown in one position with the pointed end cover 22 in place on the conduit assembly 18, in another position with the conduit assembly 18 set in the cast, and in a third position completely installed with the conically flanged end member 24 on the conduit assembly 18. In the initial phases of making up the cast, the conduit 18 is placed with the head portion thereof adjacent to a body. The cast preferably is applied to a body in the usual fashion by wrapping of the cloth material or plaster impregnated gauze or whatever around the body and pulling it over the vent structure 14 so the pointed end cover 22 will pierce and pass through the wrapping material. The configuration of the vent structure during the make up of a cast and its installation is with the shield adjacent to the body, the pointed end 22 screwed on the conduit assembly 18, with the inner conduit member 20 engaged in the end portion of the shank 28 and in contact with the recessed area 56 in the pointed end cover 22. A vent in this configuration is shown on the left side of FIG. 2. It is to be noted that the vent structure 14 is somewhat adjustable in length in order to compensate for different thicknesses of casts. The length of the vent structure 14 is provided when the inner conduit member 20 is screwed into the threaded portion 34 of the conduit assembly 18 and the pointed end cover 22 is screwed over the shank 28 so that the flange portion 48 of the inner conduit member 20 is brought into contact with the recessed portion 56 of the pointed end cover 22 thereby locking the end cover 22 and the conduit 18 together. The length of the vent structure 14 is determined primarily by the distance which the inner conduit positioner member 20 is inserted into the passageway 32 of the shank 28 because the flange 48 contacts the inner end of the end cover 22 thereby controlling its spacing relative to the head 30 of the conduit 18.
The vent structure is shown in FIG. 2 on the left side thereof in the position in which it is initially mounted in a cast 70. When in this initial position the head 30 of the conduit 18 is substantially flush with the inner portion of the cast 70 and adjacent to the body with the pointed end cover 22 extending from the outer surface of the cast. Once the cast has sufficiently set so that it is fairly rigid, the pointed end cover is unscrewed from the conduit 18 and the vent as shown in the upper portion of FIG. 2. The next step in installing the vent 14 is to engage the flanged conduit end 24 with the conduit assembly 18 as shown in the lower portion of FIG. 2; this is the final installed form of the vent structure 14. The inner conduit positioner member can be removed from the vent structure 14 if desired or left in it. Once the cast has set to its final form the vent structure 14 is substantially permanent in the cast because of surface adherence between the casting material and the components of the vent structure. It is to be noted that the pointed end cover 22 is removed and can be re-used to install other vents, whereas the conduit assembly 18 and flanged conduit end 24 are permanently installed in the cast and preferably are not to be re-used; they are disposed of along with the cast when it is no longer needed.
With the vent structure 14 installed in the cast as shown in the drawings, the shield portion thereof 26 is immediately adjacent to the flesh of a body enclosed in the cast. The shield functions to prevent the flesh from pushing into the passageway 32 by providing a closely knit obstruction. The shield 26 is constructed so as to allow air to substantially freely move through the vent and into the cavity of the cast. The plug 38 and mesh portion 40 of the shield 26 provide a passageway for air moving through the vent passageway 32 into or out of the cast cavity by spacing the end surface 42 of the head 30 a short distance away from the flesh. Normally a cast will not be extremely tight against the flesh but will be snug against it and in some cases a short distance away. When the flesh is not directly in contact with the head portion of the conduit 18, there is no restricted airflow problem. However, when the flesh is directly in contact with the head end portion of the conduit 18, there would be an airflow problem if it were not for the shield 26 providing some spacing between the surface of the head 30 and the flesh. When the shield 26 is directly in contact with the flesh, there will be an airflow restriction sufficient to reduce the possible airflow through the vent structure 14; however, the airflow will not be totally cut off as it would if the shield were not there.
Referring to FIG. 1, it is to be noted that a window generally indicated at 72 is installed in the cast along with a plurality of vent structures 14 of this invention. The window 72 is shown in a rectangular shape and includes a transparent pane portion integrally engaged with the cast 10. The window 72 is provided so that a person can look inside the cast and inspect the condition of the cast and the flesh to some extent. It is advantageous to be able to inspect the condition of the cast and the flesh enclosed by the cast during the healing process, namely, to inspect abrasions, rashes, or the like on the flesh and to examine the general condition of the cast adjacent to the flesh. The window 72 is preferably installed in a cast along with a plurality of the vent structures 14 to provide a structure which will immobilize a portion of the body, allow air ventilation and visual observation of the interior of the cast.
In the manufacture of the surgical cast vent structure 14 of this invention, it is obvious that the conduit assembly 18, inner conduit 20, and flanged conduit end 24 can be constructed of sufficient size so that a plurality of the vent structures 14 when installed in a cast will adequately ventilate it to achieve the end product. The conduit assembly 18, inner conduit member 20 and flanged conduit end 24 can be easily constructed of an inexpensive material that can be disposed of along with the cast after its use. It is also obvious from the foregoing that the pointed end cover member 22 is to be constructed of a material which will sustain the repeated use in installation of the vents. In the preferred construction of the the vent structure 14 of this invention, the conduit assembly 18, inner conduit member 20, and flanged conduit end member 24 are made from MARLEX 50, a polyethylene product of the Phillips Petroleum Company, Bartlesville, Oklahoma. MARLEX 50 is preferred in the construction of the vent structure 14 of this invention because of its non-allergenic and non-corrosive properties as well as its easy moldability, extrudability and threadability. The pointed end cover 22 is preferably constructed from a surgical steel material, stainless steel or any material which has sufficient corrosion resistance and durability which allow it to be re-used to install the vent structures 14 of this invention.
In the use and operation of the surgical cast vent structure 14 of this invention, it is seen that same provides an easily installed structure having disposable parts permanently mountable in a surgical cast. The construction of the vent structure 14 is such that it can be installed in a cast while the cast is being made up and is adjustable lengthwise so as to be installable in different thicknesses of casts and provide ventilation of the cast cavity to the atmosphere. The material of construction of the surgical cast vent structure is such that it will not interfere with the shaping and forming of the surgical cast structure and such that it will not cause problems due to corrosion of it or allergenic reactions of a person on which the cast is set.
As will be apparent from the foregoing description of the applicant's surgical cast vent structure, relatively inexpensive means have been provided to ventilate a surgical cast which are easily installed and permanently mounted in a surgical cast. The vent structures of this invention are economical to manufacture, simple to install, permanently mountable in the surgical cast structure, not distractive in appearance, and the end cover thereof can be used over to install a plurality of vent structures.
While the invention has been described in conjunction with preferred specific embodiments thereof, it will be understood that this description is intended to illustrate and not to limit the scope of the invention, which is defined by the following claims.
In one preferred specific embodiment of this invention, the vent structure includes a conduit to be mounted in a cast with a positioner insertable inside the outer end of the conduit having an end cover used in installing the vent, and having a flanged member to be connected to the conduit on the outside of the cast. The conduit has an enlarged head on one end to be placed in the cast's interior cavity with the cylindrical portion of the conduit extending outward to the cast. The positioner is engagable in the interior passageway of the conduit and contacts the conduit end cover. The conduit end cover is used for installing the vent in a cast and it is removed after the cast is made up. The conduit flange replaces the conduit end cover when the vent is in place in the cast in order to provide open fluid communication between the interior of the cast and the atmosphere. A shield is provided on the surface of the conduit head to prevent pouting of the flesh inside the cast and to provide a separation between the material of the conduit head and the person's body. The conduit, positioner and conduit flange member are preferably constructed of a non-allergenic and corrosive resistant material which is inexpensive and can be disposed of along with the cast when it is no longer needed. The conduit end cover is used only in installation of the vent structure and is constructed of durable material so it can be re-used to install other vents.
One object of this invention is to provide a surgical cast venting means overcoming the aforementioned disadvantages of the prior art devices.
Still, one other object of this invention is to provide a surgical cast venting means having a conduit apparatus to provide fluid communication between the inner cavity of a cast and the atmosphere which has a divergent outer portion to enhance airflow and a shield on the inner surface thereof to prevent pouting of the wearer's flesh inside of the cast against the vent.
Still another object of this invention is to provide a surgical cast venting means which has a conduit member that can be covered during the installation of the vent in a cast and uncovered when the vent is installed in the finished cast.
Yet, one additional object of this invention is to provide a surgical cast venting means which has a conduit cover which can be re-used to install the disposable conduits of the invention in surgical casts.
Various other objects, advantages, and features of the invention will become apparent to those skilled in the art from the following discussion, taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a side elevation view of a cast on a person's foot having a plurality of vent structures of the invention installed therein, and having a viewing window installed in the cast;
FIG. 2 is a cross-sectional view of a cast having three of the vent structures installed therein, one structure with the conduit end cover in place, another structure with the conduit end cover removed, and a third structure with the conduit flange member in place thereon;
FIG. 3 is a perspective view of the vent structure in exploded form and showing the conduit end cover member;
FIG. 4 is an exploded elevation view in cross-section of the vent structure with the pointed conduit end cover member; and
FIG. 5 is a cross-sectional elevation view of the conduit outer end flange member.
The following is a discussion and description of preferred specific embodiments of the surgical cast venting means of this invention, such being made with reference to the drawings, whereupon the same reference numerals are used to indicate the same or similar parts and/or structure. It is to be understood that such discussion and description is not to unduly limit the scope of the invention.
Referring to the drawing in detail and in particular to FIG. 1, showing a cast 10 on a foot 12 with a plurality of vent structures 14 of this invention mounted therein. The components of the vent structure 14 are shown in FIGS. 3, 4 and 5; the vent structure 14 includes a conduit assembly 18, an inner conduit positioner member 20, an end cover member 22, and a conical flanged end member 24. The conduit assembly 18 includes the conduit itself and a shield assembly 26 on its enlarged end. As can be seen clearly in FIG. 4 the conduit assembly 18 has an elongated shank portion 28 with a radially extended head portion 30 at one end thereof, and a passageway 32 extending through the shank portion 28. The shank portion 28 of the conduit assembly 18 is threaded on the inner surface 34 of the passageway 32 and on its outer surface 36. The shield assembly 26 is attached to the conduit head 30 and includes a perforated plug member 38 and an overlying mesh member 40. The plug 38 preferably has a plurality of apertures through it to provide for relatively open fluid communication. When the plug 38 is in place in the conduit assembly 18, it rests in the mouth of the passageway 32. The mesh member 40 is preferably a relatively open weave cloth like material attached to the end surface 42 of the conduit head 30 and adapted to hold the plug 38 in its relative position at the mouth of the passageway 32. The shield assembly 26 prevents pouting of the flesh, a condition whereby the skin of a person wearing a cast would be pushed outward into the passageway 32 if the shield assembly was not in place. Pouting is desirable to be avoided because it produces skin irritation followed by itching and general discomfort for the wearer of the cast.
The inner conduit member 20 has a shank portion 42 with a passageway 44 through it. The shank 42 is threaded on its outer surface 46 and has a radially extending flange 48 at one end thereof. The threaded shank portion 46 is adapted to engage the threaded passageway 32 in the conduit assembly 18. The flange 48 is sized sufficiently large so that it will prevent the inner conduit member 20 from passing completely into the threaded passageway 32. The inner conduit positioner member 20 is used as a lengthening and positioning device in the installation of the vent 14 as will be described hereinafter.
The end cover member 22 is basically a cap-like structure threaded to engage the outward extending end of the conduit assembly 18 and pointed on its outer end. Specifically, the conduit end cover member 22 has a sidewall 50 integral with the pointed end 52 with the sidewall threaded on its interior 54 to engage the outer threaded portion 36 of the conduit assembly shank 28. A recessed area 56 is provided inside the point end portion of the end cover to receive the flange portion 48 of the inner conduit 20. The pointed end cover 22 is re-used again and again in installing the vents in a cast. For the reasons of re-usability the end cover 22 is preferably constructed of a rigid and durable material, for example, surgical steel or the like.
The conically flanged conduit end member 24 is shown in detail in FIG. 5. It includes a sidewall 60 threaded on its interior surface 62 and having an integral and conically outwardly flanged portion 64. The conically flanged conduit end 24 replaces the pointed end cover 22 once the vent structure 14 is in place in a cast. The conically flanged conduit end 24 is screwed onto the shank portion 28 of the conduit 18 once the conduit assembly 18 has been set in a cast. The threaded portion 62 of the conically flanged conduit is adapted to be engaged with the outer threaded portion 36 of the conduit assembly 18. The conically flanged end 24 is preferably constructed of the same type of material as the conduit assembly 18 and the inner conduit member 20 for similar reasons.
The process of installing the vent structure 14 in a cast is generally illustrated in FIG. 2 wherein the vent structure 14 is shown in one position with the pointed end cover 22 in place on the conduit assembly 18, in another position with the conduit assembly 18 set in the cast, and in a third position completely installed with the conically flanged end member 24 on the conduit assembly 18. In the initial phases of making up the cast, the conduit 18 is placed with the head portion thereof adjacent to a body. The cast preferably is applied to a body in the usual fashion by wrapping of the cloth material or plaster impregnated gauze or whatever around the body and pulling it over the vent structure 14 so the pointed end cover 22 will pierce and pass through the wrapping material. The configuration of the vent structure during the make up of a cast and its installation is with the shield adjacent to the body, the pointed end 22 screwed on the conduit assembly 18, with the inner conduit member 20 engaged in the end portion of the shank 28 and in contact with the recessed area 56 in the pointed end cover 22. A vent in this configuration is shown on the left side of FIG. 2. It is to be noted that the vent structure 14 is somewhat adjustable in length in order to compensate for different thicknesses of casts. The length of the vent structure 14 is provided when the inner conduit member 20 is screwed into the threaded portion 34 of the conduit assembly 18 and the pointed end cover 22 is screwed over the shank 28 so that the flange portion 48 of the inner conduit member 20 is brought into contact with the recessed portion 56 of the pointed end cover 22 thereby locking the end cover 22 and the conduit 18 together. The length of the vent structure 14 is determined primarily by the distance which the inner conduit positioner member 20 is inserted into the passageway 32 of the shank 28 because the flange 48 contacts the inner end of the end cover 22 thereby controlling its spacing relative to the head 30 of the conduit 18.
The vent structure is shown in FIG. 2 on the left side thereof in the position in which it is initially mounted in a cast 70. When in this initial position the head 30 of the conduit 18 is substantially flush with the inner portion of the cast 70 and adjacent to the body with the pointed end cover 22 extending from the outer surface of the cast. Once the cast has sufficiently set so that it is fairly rigid, the pointed end cover is unscrewed from the conduit 18 and the vent as shown in the upper portion of FIG. 2. The next step in installing the vent 14 is to engage the flanged conduit end 24 with the conduit assembly 18 as shown in the lower portion of FIG. 2; this is the final installed form of the vent structure 14. The inner conduit positioner member can be removed from the vent structure 14 if desired or left in it. Once the cast has set to its final form the vent structure 14 is substantially permanent in the cast because of surface adherence between the casting material and the components of the vent structure. It is to be noted that the pointed end cover 22 is removed and can be re-used to install other vents, whereas the conduit assembly 18 and flanged conduit end 24 are permanently installed in the cast and preferably are not to be re-used; they are disposed of along with the cast when it is no longer needed.
With the vent structure 14 installed in the cast as shown in the drawings, the shield portion thereof 26 is immediately adjacent to the flesh of a body enclosed in the cast. The shield functions to prevent the flesh from pushing into the passageway 32 by providing a closely knit obstruction. The shield 26 is constructed so as to allow air to substantially freely move through the vent and into the cavity of the cast. The plug 38 and mesh portion 40 of the shield 26 provide a passageway for air moving through the vent passageway 32 into or out of the cast cavity by spacing the end surface 42 of the head 30 a short distance away from the flesh. Normally a cast will not be extremely tight against the flesh but will be snug against it and in some cases a short distance away. When the flesh is not directly in contact with the head portion of the conduit 18, there is no restricted airflow problem. However, when the flesh is directly in contact with the head end portion of the conduit 18, there would be an airflow problem if it were not for the shield 26 providing some spacing between the surface of the head 30 and the flesh. When the shield 26 is directly in contact with the flesh, there will be an airflow restriction sufficient to reduce the possible airflow through the vent structure 14; however, the airflow will not be totally cut off as it would if the shield were not there.
Referring to FIG. 1, it is to be noted that a window generally indicated at 72 is installed in the cast along with a plurality of vent structures 14 of this invention. The window 72 is shown in a rectangular shape and includes a transparent pane portion integrally engaged with the cast 10. The window 72 is provided so that a person can look inside the cast and inspect the condition of the cast and the flesh to some extent. It is advantageous to be able to inspect the condition of the cast and the flesh enclosed by the cast during the healing process, namely, to inspect abrasions, rashes, or the like on the flesh and to examine the general condition of the cast adjacent to the flesh. The window 72 is preferably installed in a cast along with a plurality of the vent structures 14 to provide a structure which will immobilize a portion of the body, allow air ventilation and visual observation of the interior of the cast.
In the manufacture of the surgical cast vent structure 14 of this invention, it is obvious that the conduit assembly 18, inner conduit 20, and flanged conduit end 24 can be constructed of sufficient size so that a plurality of the vent structures 14 when installed in a cast will adequately ventilate it to achieve the end product. The conduit assembly 18, inner conduit member 20 and flanged conduit end 24 can be easily constructed of an inexpensive material that can be disposed of along with the cast after its use. It is also obvious from the foregoing that the pointed end cover member 22 is to be constructed of a material which will sustain the repeated use in installation of the vents. In the preferred construction of the the vent structure 14 of this invention, the conduit assembly 18, inner conduit member 20, and flanged conduit end member 24 are made from MARLEX 50, a polyethylene product of the Phillips Petroleum Company, Bartlesville, Oklahoma. MARLEX 50 is preferred in the construction of the vent structure 14 of this invention because of its non-allergenic and non-corrosive properties as well as its easy moldability, extrudability and threadability. The pointed end cover 22 is preferably constructed from a surgical steel material, stainless steel or any material which has sufficient corrosion resistance and durability which allow it to be re-used to install the vent structures 14 of this invention.
In the use and operation of the surgical cast vent structure 14 of this invention, it is seen that same provides an easily installed structure having disposable parts permanently mountable in a surgical cast. The construction of the vent structure 14 is such that it can be installed in a cast while the cast is being made up and is adjustable lengthwise so as to be installable in different thicknesses of casts and provide ventilation of the cast cavity to the atmosphere. The material of construction of the surgical cast vent structure is such that it will not interfere with the shaping and forming of the surgical cast structure and such that it will not cause problems due to corrosion of it or allergenic reactions of a person on which the cast is set.
As will be apparent from the foregoing description of the applicant's surgical cast vent structure, relatively inexpensive means have been provided to ventilate a surgical cast which are easily installed and permanently mounted in a surgical cast. The vent structures of this invention are economical to manufacture, simple to install, permanently mountable in the surgical cast structure, not distractive in appearance, and the end cover thereof can be used over to install a plurality of vent structures.
While the invention has been described in conjunction with preferred specific embodiments thereof, it will be understood that this description is intended to illustrate and not to limit the scope of the invention, which is defined by the following claims.