Patent Description:
It is usually deemed desirable for such gases conveyed to a patient include some degree of water vapor to avoid drying tissues of a patient's respiratory system. Also, the respiratory gases that a patient breathes out also typically include some amount of water vapor. An issue arising from the water vapor in the respiratory gases conveyed both to and from a patient is that of condensation within the hoses. If the temperature of the gases in one of the hoses falls below the dew point of the gases within that hose, then water vapor condenses within that hose, and possibly leads to pooling of liquid water within the lowest portion of the hose. As a result, the flow of gases through that hose may be constricted or even cut off entirely in a manner very much akin to the pooling of water within a sink drain trap. Alternatively or additionally, depending on where such pooling occurs within a hose, it is possible for a patient to be caused to breathe in pooled water from within a hose and/or for pooled water within a hose to be sent into the medical device. Such developments may be acutely and immediately harmful to the patient such that the patient may be caused to actually drown from inhalation of liquid water into the lungs, and/or the medical device may be damaged by the intake of liquid water, instead of gases breathed out by the patient.

Among prior art efforts to address such issues is the addition of water traps to each such hose. A water trap serves, in essence, as a designated location along the length of a hose where liquid water can be allowed to pool relatively harmlessly out of the path of flow of gases through the hose to at least minimize any possible obstruction to the passage of gases through the hose. Unfortunately, the use of water traps suffers various drawbacks. For a water trap to work effectively, it must be positioned at a point along its respective hose that is lowest in elevation such that any liquid water that is caused to condense from the respiratory gases is caused by the force of gravity to proceed toward the water trap, instead of pooling elsewhere within the hose. This requires some deliberate effort on the part of those who use such hoses and caregivers who prepare such hoses for use to ensure that the manner in which such hoses are installed and used does indeed result in the water traps being at the point of lowest elevation along the hoses. However, even if this is successful, each of the water traps holds a finite volume of liquid, and is therefore required to be opened and emptied on a regular basis to prevent overfilling. Also of concern is the possibility of the liquid within a water trap collecting and growing pathogens that may then propagate into the respiratory gases passing through the hoses, and thereby potentially infect the patient.

Another prior art effort to address such issues is to lay heating wires inside each of such hoses to raise the temperature of the gases therein to be higher than the dew point, thereby avoiding the occurrence of condensation altogether. Unfortunately, it has been found that simply laying heating wires within a hose results in uneven heating of the gases therein, thereby possibly leaving portions of the hose with a temperature that is still low enough relative to the dew point of the gases therein to allow condensation to occur.

Document <CIT> discloses a helically fabricated electrically conductive flexible hose which includes at least one plastic strip wrapped helically with successive convolutions overlapping to form a flexible hose wall of at least one ply. At least one self-supporting electrically conductive helical reinforcing element forms the outermost element of the hose and is concentric with and engages the outside of the wall. This element is of composite construction comprising at least two spaced inner metal wires and an outer plastic sheath of non-circular cross-section enclosing the wires and having a substantially flat side facing inwardly and engaging the outer ply of the wall. The plastic sheath is bonded to the plastic wall. In a preferred form of the invention a separate plastic insulation layer surrounds each metal wire within the plastic sheath.

Other issues exist in prior art heated respiratory hose assemblies beyond that ofcondensation. The heating of such assemblies often entails the use of a temperature sensor that must be inserted at the correct location among the circulatory flow of gases to and from the patient to be effective. Also, many medical devices also employ a gas flow sensor to provide continual confirmation of there being a flow of respiratory gases from the medical device to the patient, and this sensor must also be positioned at the correct location among the circulatory flow of gases to and from the patient to be effective. Unfortunately, many prior art heated respiratory hose assemblies use numerous individual fittings to connect the lengths of hose together to form the assembly, and to connect the assembly to both the medical device and the face mask, endotracheal tube or tracheostomy stoma at the patient end of the assembly. These numerous fittings often include separate fittings for the locations of the flow and temperature sensors, thereby providing opportunities for errors to occur in the connection and placement of these sensors.

The present invention addresses such needs and deficiencies as are explained above by providing a heated respiratory hose assembly that includes a pair of heated hoses and various fittings to convey respiratory gases in a closed circuit between a medical device, such as a ventilator or CPAP device, and a patient. Such a hose assembly may be used in a medical environment, such as a hospital, outpatient care facility or other medical facility, or a non-medical environment, such as a patient's home or workplace. Such a hose assembly may incorporate a relatively minimal set of components to reduce opportunities for errors in assembling those components, as well as connecting various sensors thereto, as part of preparing the hose assembly for use.

Each hose of the heated respiratory hose assembly may incorporate electrical wires into its support helix, which may include heating wires to enable even distribution of the heat generated by the heating wires within the interior of the hose. Such heating wires may be positioned within the support helix at a location closer to the interior of the hose and in a manner that uses much of the material of the support helix as an insulator against the environment external to the hose to cause a greater proportion of the heat generated by the heating wires to radiated into the interior of the hose, rather than wastefully radiated into the environment external to the hose. To achieve such placement, a bead of plastics material that forms the support helix may be extruded around the heating wires as the heating wires are fed through the extruder that extrudes the bead of plastics material during formation of the hose. Additionally, tension may be exerted on the heating wires during formation of the hose to cause the heating wires to be drawn through plastics material of the bead, while still molten, and closer to the interior of the hose.

In other embodiments, the bead of plastics material that forms the support helix may be more fully formed at a stage that precedes the formation of the wall of the hose such that the heating and/or other electrical wires may already be positioned as desired within the support helix before the support helix is combined with the one or more extrusions used to form the wall. More specifically, the bead of plastics material may be extruded around the heating and/or other electrical wires as those wires are fed through the extruder that extrudes the bead. However, instead of directly winding the newly formed bead around the wall of the hose, the newly formed bead may be routed through a trough of water (or other cooling device) to cool the plastics material of the newly formed bead enough to cause the plastics material to be hardened enough to prevent the heating and/or other electrical wires from migrating within the plastics material. In this way, the cross- section of the newly formed bead is stabilized such that the position of the heating and/or other electrical wires therein is set.

Following such cooling, the newly formed and cooled bead may then be fed through a heating tube in which the bead is re-heated to a controlled degree that causes outer surface portions thereof to slightly molten such that the outer surface portions are softened and become tacky, while avoiding heating the bead to such an extent that inner portions thereof are also caused to become molten such that the heating and/or other electrical wires therein are caused to be able to migrate to new positions therein. By softening the outer surface portions, the now re-heated bead is now less resistant to being wrapped around the exterior of the wall of a hose. By making the outer surface portions tacky, the now re-heated bead is caused to readily bond to the exterior wall of the hose as it is wrapped around the exterior wall of the hose, thereby becoming the support helix of the heated hose and completing the formation of the heated hose.

Alternatively, following such cooling, the newly formed and cooled bead may, instead of being immediately re-heated and used as the support helix in the formation of a heated hose, be stored in a roll (e.g., wound on a spindle, etc.) for storage for later use in the formation of a heated hose at a later time. It may be deemed desirable to store rolls of multiple types of beads, each having a different external cross-sectional shape, and/or a different assortment of heating and/or other electrical wires formed therein, and/or with different positional arrangements of heating and/or other electrical wires therein. Such storage of such a variety of beads may enable the on- demand or just-in-time manufacturing of heated hoses where the type of bead to be included is able to be selected from among such a variety for each heated hose that is to be made.

Regardless of whether the newly formed and cooled bead is used immediately in forming a heated hose or stored for later use in forming a heated hose, in some embodiments, the re-heating of the outer surface portions of the newly formed and cooled bead may entail feeding the newly formed and cooled bead through a heating tube into which hot air is blown. The temperature and/or volume of the hot air blown into the heating tube may be adjusted to control the degree to which outer surface portions of the bead are caused to become molten. Such hot air temperature and/or volume control may be based on various factors, including and not limited to, the cross-section of the heating tube, the cross-section of the bead, the length of the heating tube and/or the speed at which the bead is fed through the heating tube.

Each hose of the heated respiratory hose assembly may incorporate a pair of hose fittings, one at each end of each hose. Each such hose fitting may be formed of rigid plastics material and may be shaped and sized to enable connection of its corresponding end of a hose to a medical device or to a face mask, endotracheal tube, tracheostomy stoma or other component worn by or otherwise carried by a patient, and may do so directly or through at least one other component interposed therebetween. Each such hose fitting may be permanently coupled to its corresponding end of a hose by an undermold coupling formed of flexible plastics material to provide a gas-tight seal between the fitting and its corresponding end of the hose, and/or to provide a strain relief to prevent damage to the hose where the end of the hose is coupled to its corresponding fitting.

Each undermold coupling may be formed as a single piece of the flexible plastics material, and may include a generally cylindrical tubular portion and at least one ladder-like grating.

Threads may be formed on the interior surface of the cylindrical tubular portion to enable the cylindrical tubular portion to be threaded onto the exterior of an end of a hose as part of coupling the undermold coupling to an end of a hose. Each hose fitting may be formed as a single piece of the rigid plastics material, and may include a generally cylindrical tubular portion. The cylindrical tubular portion may have a slightly larger diameter than the cylindrical tubular portion of its corresponding undermold coupling to receive and closely surround the cylindrical tubular portion of its corresponding undermold coupling therein.

A set of slots may be formed through a portion of the cylindrical wall of the cylindrical tubular portion of each hose fitting to interact with the at least one ladder-like grating of the corresponding undermold coupling as part of forming a permanent mechanical coupling between the fitting and the corresponding undermold coupling. As the cylindrical tubular portion of an undermold coupling is received within the cylindrical tubular portion of a hose fitting, a ladder- like grating of the undermold coupling may be hinged or may be otherwise partly pulled away from contact with the exterior of the cylindrical tubular portion of the undermold coupling to allow portions of the ladder-like grating to be positioned to overlie, and then extend into and through the slots formed through the cylindrical wall of the cylindrical tubular portion of the hose fitting. In so extending through the slots, those portions of the ladder-like grating are allowed to come back into contact with the exterior of the cylindrical tubular portion of the undermold coupling. Such an assembled combination of a hose fitting and a corresponding undermold coupling may then be heated to cause bonding of the flexible plastics material of the undermold coupling to the rigid plastics material of the hose fitting to form a gas-tight seal therebetween, and to cause bonding between the portions of the ladder- like grating that extend through the slots and the exterior surface of the cylindrical tubular portion of the undermold to aid in permanently mechanically interlocking the hose fitting to the undermold.

At one end of each hose, the support helix may be partially unwound, and the unwound end of the support helix may be extended at least partially within the corresponding hose fitting to an electrical connector through which the heating and/or other electrical wires within the support helix may be provided with electrical power and/or may exchange various electrical signals. At the electrical connector, the ends of the heating and/or other electrical wires at the unwound end of the support helix may each be directly soldered to, or otherwise directly electrically connected to, an electrical contact of the electrical connector to. In embodiments in which the hose fitting is a Y- fitting, a T-fitting, or some other form of three-way fitting, such an electrical connector may be carried within a plug that may be carried within, and may entirely close, one of the three cylindrical connections of the hose fitting. In this way, one of the three cylindrical connections of the hose fitting through which gases may have otherwise been caused to flow may be repurposed to serve as an electrical connection point.

In other embodiments, the electrical connector may be located entirely outside of the hose fitting. In such embodiments, the unwound end of the support helix may be caused to further extend out of the hose fitting and to the location of the electrical connector in the environment external to the hose fitting and external to the corresponding hose. The portion of the unwound end of the support helix that extends out of the hose fitting may be sheathed in heat- shrink tubing or other material to provide a degree of physical protection to that portion of the unwound end of the support helix. Such heat-shrink tubing or other material providing such a sheath may also provide thermal insulation to prevent a patient or other person who comes into contact with that portion of the unwound end of the support helix being burned by the heat emitted by heating wires that may extend therethrough. In this way, the portion of the unwound end of the support helix that extends outside of the hose fitting is repurposed to serve as a "pigtail" to enable an electrical connection to a medical device to provide electric power to the heating wires and/or to enable an exchange of electrical signals with other electrical wires within the support helix.

A fuller understanding of what is disclosed in the present application may be had by referring to the description and claims that follow, taken in conjunction with the accompanying drawings, wherein:.

<FIG> through IE, taken together, depict aspects of a novel heated respiratory hose assembly <NUM> that addresses many of the shortcomings of prior art assemblies, including those discussed above. As depicted in <FIG>, the heated respiratory hose assembly <NUM> may include two sub- assemblies, specifically an inspiratory hose assembly <NUM> by which respiratory gases may be conveyed from a medical device to a patient to breathe in, and an expiratory hose assembly <NUM> by which respiratory gases breathed out by the patient may be conveyed back to the medical device. This circular flow is also conceptually depicted in <FIG>.

The inspiratory hose assembly <NUM> includes an inspiratory inlet fitting <NUM> for connection to a medical device <NUM> (e.g., a ventilator or CPAP device), an inspiratory outlet fitting <NUM> for connection to a parallel Y-fitting <NUM> at the patient end, and an inspiratory hose <NUM> to convey respiratory gases received by the inspiratory inlet fitting <NUM> from the medical device <NUM> and to the inspiratory outlet fitting <NUM> to be conveyed onward to the patient through the parallel Y- fitting <NUM>. Correspondingly, the expiratory hose assembly <NUM> includes an expiratory inlet fitting <NUM> for connection to the parallel Y-fitting <NUM> at the patient end, an expiratory outlet fitting <NUM> for connection to the medical device <NUM>, and an expiratory hose <NUM> to convey respiratory gases received by the expiratory inlet fitting <NUM> from the patient through parallel Y- fitting <NUM> and to the expiratory outlet fitting <NUM> to be conveyed onward to the medical device <NUM>. At the patient end, the parallel Y-fitting <NUM> may connect the heated respiratory hose assembly <NUM> to a face mask <NUM>, an endotracheal tube <NUM>, a tracheostomy stoma <NUM> (see <FIG>) or other component.

Each of FIGURES IB and 1C provide a perspective view of one embodiment of the heated respiratory hose assembly <NUM> in which the inspiratory inlet fitting <NUM> and the expiratory outlet fitting <NUM> are both implemented with <NUM>-degree Y-fitting s in which there is both a straight- through path for either gases or wiring to pass from the hoses <NUM> and <NUM>, respectively, and an angled path that branches off from the straight-through path at a <NUM>-degree angle relative to the connections to the hoses <NUM> and <NUM>, respectively. Each of FIGURES ID and IE provide an exploded perspective view of this embodiment. In this embodiment, one of the connections of each of the Y-fittings <NUM> and <NUM> is occupied by a plug <NUM> and <NUM> that carries an electrical connector <NUM> and <NUM>, respectively. In the depicted variant of this embodiment, at the inspiratory inlet fitting <NUM>, the straight-through connection (relative to the connection to the inspiratory hose <NUM>) is occupied by the plug <NUM> that carries the electrical connector <NUM> by which electric power is able to be provided to a pair of heating wires incorporated into the support helix of the inspiratory hose <NUM>, as will be explained in greater detail. Correspondingly, in this depicted variant of this embodiment, at the expiratory outlet fitting <NUM>, the <NUM>-degree connection (relative to the connection to the expiratory hose <NUM>) is occupied by the plug <NUM> that carries the electrical connector <NUM> by which electric power is able to be provided to a pair of heating wires incorporated into the helix of the expiratory hose <NUM>, as will also be explained in greater detail.

It should be noted that, despite such a depiction of the use of particular ones of the three connections of each of the Y-fittings <NUM> and <NUM> in <FIG> as being occupied by plugs carrying electrical connectors, different connections of the Y-fittings <NUM> and <NUM> may be so occupied in other variants of the embodiment of the heated respiratory hose assembly <NUM> of <FIG>. Also, and as will be depicted in subsequent figures, it should be noted that other embodiments of the heated respiratory hose assembly <NUM> may employ hose fitting(s) <NUM> and/or <NUM> of an entirely different type that may each provide a different selection of connections from which one may be chosen to be occupied by a plug carrying an electrical connector. <FIG>, taken together, depict aspects of the use of sensors with at least the inspiratory hose assembly <NUM> of the heated respiratory hose assembly <NUM> to monitor the flow and/or temperature of at least respiratory gases from the medical device <NUM> to the patient. As depicted, the inspiratory inlet fitting <NUM> may additionally include a flow sensor port <NUM> formed through a portion of the wall of the inspiratory inlet fitting <NUM>. The flow sensor port <NUM> provides an opening into the inspiratory interior of the inlet fitting <NUM> through which a flow sensor <NUM> of a sensor harness <NUM> is able to be inserted to continually confirm the flow of respiratory gases from the medical device <NUM> and toward the patient at the patient end. As will be explained in greater detail, the flow sensor <NUM> is directional in nature such that it must be installed within the flow sensor port <NUM> in a correct orientation to function properly.

As depicted, the inspiratory outlet fitting <NUM> may additionally include a temperature sensor port <NUM> formed through the wall of the inspiratory outlet fitting <NUM>. The temperature sensor port <NUM> provides an opening into the interior of the inspiratory outlet fitting <NUM> by which a temperature sensor <NUM> of the sensor harness <NUM> is able to be inserted to continually monitor the temperature of the respiratory gases output by the medical device <NUM> at a location towards the patient end (i.e., just before those respiratory gases are conveyed through the inspiratory outlet fitting <NUM> and into the parallel Y-fitting <NUM> to be conveyed onward to the patient).

In some embodiments, and as can best be seen in <FIG>, the inspiratory inlet fitting <NUM> may carry a port plug <NUM> that may be used to close and seal the flow sensor port <NUM> in situations where at least the inspiratory hose assembly <NUM> is used without the flow sensor <NUM> installed within the flow sensor port <NUM>. Alternatively or additionally, the inspiratory outlet fitting <NUM> may carry a port plug <NUM> that may similarly be used to close and seal the temperature sensor port <NUM> in situations where at least the inspiratory hose assembly <NUM> is used without the temperature sensor <NUM> installed within the temperature sensor port <NUM>. As depicted, the port plugs <NUM> and <NUM> may be carried by the hose fittings <NUM> and <NUM>, respectively, by being attached thereto with elongate stretches of the rigid plastics material of the hose fittings <NUM> and <NUM> that are long and thin enough as to be sufficiently flexible that the port plugs <NUM> and <NUM> are able to be maneuvered to and from the ports <NUM> and <NUM>, respectively, for a relatively limited number of times without the elongate stretches breaking. As also depicted, the flow sensor <NUM> and the temperature sensor <NUM> may be physically connected by a length of cabling <NUM> of the sensor harness <NUM> that is meant to follow the length of the inspiratory hose <NUM>, and by which signals of the temperature sensor <NUM> are conveyed toward the location of the flow sensor <NUM>. As can also be seen, there may also be another length of cabling <NUM> of the sensor harness <NUM> that extends from the flow sensor <NUM> and towards the medical device <NUM> to convey the signals of both sensors <NUM> and <NUM> to the medical device <NUM>.

Referring more specifically to <FIG>, during operation of the medical device <NUM>, respiratory gases to be breathed in by a patient are conveyed from the medical device <NUM>, through the inspiratory inlet fitting <NUM>, then the inspiratory hose <NUM>, then the inspiratory outlet fitting <NUM>, then the parallel Y-fitting <NUM>, and then to the patient via still another component, such as a face mask <NUM>, an endotracheal tube <NUM>, a tracheostomy stoma <NUM> or other component. Also during operation of the medical device <NUM>, respiratory gases breathed out by the patient are conveyed from the patient through such a component (e.g., the face mask <NUM>, the tracheal tube <NUM>, the tracheostomy stoma <NUM> or other component), then the parallel Y-fitting <NUM>, then the expiratory inlet fitting <NUM>, then the expiratory hose <NUM>, then the expiratory outlet fitting <NUM>, and onward to the medical device <NUM>.

While this circular flow of respiratory gases goes on between the medical device <NUM> and the patient, the medical device <NUM> monitors the flow sensor <NUM> to ensure that respiratory gases to be breathed in by the patient are, in fact, output by the medical device <NUM> and into the inspiratory hose assembly <NUM> of the heated respiratory hose assembly <NUM> towards the patient. If a lack of flow and/or flow in a wrong direction is detected by the sensor <NUM>, then the medical device <NUM> may sound an alarm and/or provide some other audio and/or visual indication of the lack of flow and/or the incorrect direction of flow. Also while this circular flow of respiratory gases goes on between the medical device <NUM> and the patient, the medical device monitors the temperature sensor <NUM> to ensure that the respiratory gases that reach the patient end of the inspiratory hose <NUM> are of a correct temperature, both to prevent condensation within the inspiratory hose <NUM>, and for the health of the patient.

Referring more specifically to <FIG>, as just discussed, the directional nature of the flow sensor <NUM> requires correct installation of the flow sensor <NUM> within the interior of the inspiratory inlet fitting <NUM> to ensure that it is caused to sense the flow of respiratory gases towards the patient with a correct orientation. Otherwise, it may be that the flow sensor <NUM> is caused to at least attempt to detect a flow of respiratory gases in a direction opposite of the correct direction towards the patient. The inspiratory inlet fitting <NUM> may carry a flow sensor guide <NUM> adjacent to the flow sensor port <NUM> to cooperate with the shape of a portion of the exterior of the flow sensor <NUM> to aid in correctly positioning the flow sensor <NUM> relative to the flow sensor port <NUM> and the interior of the inspiratory inlet fitting <NUM>. Alternatively or additionally, the flow sensor port <NUM> may be formed to include a short tube-like portion with a bevel cut <NUM> to interact with an orientation key <NUM> carried on a portion of the exterior of the flow sensor <NUM> to aid in correctly positioning the flow sensor <NUM> relative to the flow sensor port <NUM> and the interior of the inspiratory inlet fitting <NUM>.

The medical device <NUM> may selectively turn on and off the provision of electric power to heating wires within the inspiratory hose <NUM> and the expiratory hose <NUM> to selectively apply heat thereto based on the temperature sensed by the temperature sensor <NUM>. More specifically, and as will be explained in greater detail, each of the hoses <NUM> and <NUM> may incorporate at least a pair of heating wires that may be connected to the medical device <NUM> at one end of each of the hoses <NUM> and <NUM>, and that may be soldered, crimped or otherwise electrically connected at the other end of each of the hoses <NUM> and <NUM> to form a separate closed loop of electric current through each of the hoses <NUM> and <NUM>.

Some medical devices <NUM> may turn on and off the provision of electric power to the heating wires of both hoses together. Indeed, some medical devices <NUM> may selectively provide the very same voltage from the very same power source to the heating wires of both hoses.

However, it may be the case that each of the two hoses <NUM> and <NUM> are to be heated to different temperatures. Thus, the heating wires employed in the two hoses <NUM> and <NUM> may be of different resistances and/or have other differing characteristics to bring about such a difference in temperature. More specifically, it may be deemed desirable to heat the respiratory gases being conveyed to the patient through the inspiratory hose <NUM> to a higher temperature than the respiratory gases being conveyed from the patient through the expiratory hose <NUM>. The heating of gases conveyed to the patient may be deemed of greater importance for such purposes as achieving a particular higher temperature to help the patient maintain a particular body temperature, aid in treating the patient for a particular respiratory illness, etc. Such heating of the gases conveyed to the patient would also be intended to prevent condensation from occurring within the inspiratory hose <NUM>. In contrast, the heating of gases conveyed from the patient may be solely for the purpose of preventing condensation from occurring within the expiratory hose <NUM>. Each of <FIG> depict another possible embodiment of the heated respiratory hose assembly <NUM> in which other possible different versions (or combinations of versions) of the inspiratory inlet fitting <NUM> and the expiratory outlet fitting <NUM> may be used. <FIG> provides an exploded perspective view of an alternate embodiment of the heated respiratory hose assembly <NUM> in which the inspiratory inlet fitting <NUM> and the expiratory outlet fitting <NUM> are both T-fittings, instead of the <NUM>-degree Y-fittings depicted in <FIG> through IE. <FIG> provides a perspective view of another alternate embodiment of the heated respiratory hose assembly <NUM> in which the inspiratory inlet fitting <NUM> and the expiratory outlet fitting <NUM> are both through-fittings, and from each of which a pigtail <NUM> and <NUM> emerges by which the electrical connection to the heating wires of the hoses <NUM> and <NUM>, respectively, are separately made. <FIG> provides a perspective view of the expiratory hose assembly <NUM> of still another embodiment of the heated respiratory hose assembly <NUM> in which at least the expiratory outlet fitting <NUM> is a through-fitting from which the pigtail <NUM> by which electrical connection is made to the heating wires of the expiratory hose <NUM> emerges in a direction perpendicular to the direction from which the expiratory hose <NUM> emerges. In contrast, the pigtails <NUM> and/or <NUM> depicted in the embodiment of <FIG> emerge from the hose respective fittings <NUM> and/or <NUM> in a direction that is parallel to (and alongside) the hoses <NUM> and/or <NUM>, respectively.

It should be noted that, despite such depictions of particular alternate embodiments, still other alternate embodiments of the heated respiratory hose assembly <NUM> are possible in which still other types of fittings are employed as one or both of the inspiratory inlet fitting <NUM> and the expiratory outlet fitting <NUM>. Further, it should be noted that, despite the depictions of the inspiratory outlet fitting <NUM> and of the expiratory inlet fitting <NUM> being unchanged throughout these multiple depicts of differing embodiments of the heated respiratory hose assembly <NUM>, other embodiments are possible in which other types of fittings may be employed as one or both of the inspiratory outlet fitting <NUM> and the expiratory inlet fitting <NUM>. Further, it should be noted that, despite the depictions of the inspiratory inlet fitting <NUM> and the expiratory outlet fitting <NUM> being of the same type, still other embodiments of the heated respiratory hose assembly <NUM> are possible in which the inspiratory inlet fitting <NUM> and the expiratory outlet fitting <NUM> are of different types (e.g., one may be a Y-fitting and the other may be a T-fitting, or one may be a Y- fitting or T-fitting that carries a plug with an electrical connector and the other may be a through- fitting with a pigtail that carries another plug). <FIG>, taken together, depict various aspects of one embodiment of a process for making the inspiratory hose <NUM> and/or the expiratory hose <NUM>, including aspects of forming the support helixes <NUM> and/or <NUM> thereof to include one or more electrical wires <NUM> and/or <NUM>, respectively. It should be noted that, although the helixes <NUM> and <NUM> are depicted as each incorporating a pair of heating wires <NUM> and <NUM>, respectively, other embodiments of the hoses <NUM> and/or <NUM> are possible in which different numbers of electrical wires (whether heating wires, or other varieties of electrical wires) may be incorporated into the helixes <NUM> and/or <NUM>, respectively, as well as other embodiments in which there may be multiple helixes that each carry one or more different electrical wires (again, whether heating wires, or not).

As depicted most clearly in <FIG>, each of the hoses <NUM> and <NUM> may include a wall <NUM> and <NUM>, respectively, that is physically supported by a corresponding one of the support helixes <NUM> and <NUM>. As also depicted, the support helixes <NUM> and <NUM> may spirally wrap around the exterior of the walls <NUM> and <NUM>, respectively, in a manner that leaves a continuous helical stretch of the walls <NUM> and <NUM> between adjacent coils of the support helixes <NUM> and <NUM> that enable the hoses <NUM> and <NUM>, respectively, to be flexible enough to bend. Additionally, such spacing between adjacent coils of the support helixes <NUM> and <NUM> may be of a distance selected to allow fold(s), curve(s) and/or convolution(s) to be formed in the continuous helical stretch of the walls <NUM> and <NUM> therebetween to enable the hoses <NUM> and <NUM>, respectively, to be axially stretched and compressed (i.e., lengthened or shortened along the depicted axis <NUM>), as well as to bend.

As depicted most clearly in <FIG>, the heating wires <NUM> and <NUM> may be positioned within the flexible plastics material of the support helixes <NUM> and <NUM> to bring them closer to the interior of the hoses <NUM> and <NUM>, respectively, than to the environment external thereto. In this way, much of the flexible plastics material that makes up the support helixes <NUM> and <NUM> is used as insulation to tend to cause the heat generated by the heating wires <NUM> and <NUM> to be radiated into the interiors of the hoses <NUM> and <NUM>, respectively, instead of being wasted by being radiated into the environment external to the hoses <NUM> and <NUM>.

As also depicted most clearly in <FIG>, each individual heating wire <NUM> and <NUM> may incorporate a conductor <NUM> and <NUM>, and an individual insulator <NUM> and <NUM> in addition to the insulation provided by the flexible plastics material of the support helix <NUM> and <NUM>, respectively. In some embodiments, the heating wire <NUM> and <NUM> may be a variant of magnet wire or similar wire with a selected resistance where the insulator <NUM> and <NUM>, respectively, may be one or more layers of polymer or other type of film. As will be recognized by those skilled in the art, the insulators <NUM> and <NUM> may be selected to be capable of resisting temperatures expected to be encountered during heating of the hoses <NUM> and <NUM>, respectively, but to not be capable resisting temperatures typically encountered during soldering such that electrical connections may be made to the wires <NUM> and <NUM> using any of a variety of soldering techniques without requiring stripping of the insulation <NUM> and <NUM>, respectively, in preparation therefor.

As depicted most clearly in <FIG> and <FIG>, each of the hoses <NUM> and <NUM> may be formed using a modified variant of a typical hose manufacturing apparatus such as the depicted hose manufacturing apparatus <NUM>. As will be familiar to those skilled in the art, such a hose manufacturing apparatus <NUM> may incorporate a set of rotating rollers <NUM> that may be canted in adjustable orientations relative to each other and relative to the axis <NUM> to form a hose therearound from one or more spirally wound extruded lengths of plastics material. As will also be familiar to those skilled in the art, such hose forming typically entails wrapping at least one extruded length of webbing material for the wall of the hose and at least one extruded length of a support bead for at least one support helix of the hose. Alternatively, a single extrusion of material that combines the webbing and support bead may be used, as will also be familiar to those skilled in the art. An example of such hose manufacturing apparatus is disclosed in <CIT> issued.

November <NUM>, <NUM> to Carl J. Garrett, from which <FIG> was copied to provide 4C of this present application. Additional aspects of hose making on which the making of the hoses <NUM> or <NUM> may also be based are disclosed in <CIT>, and <CIT> However, to enable the forming of the hoses <NUM> and <NUM>, such a typical hose making apparatus <NUM> may be modified to enable the extrusion of the flexible plastics material of the support helixes <NUM> and <NUM> around the heating wires <NUM> and <NUM>, respectively, prior to the winding of the support helixes <NUM> and <NUM> onto the rollers <NUM>.

As depicted most clearly in <FIG> and <FIG>, as part of such modifications to the hose making apparatus <NUM>, each of the heating wires <NUM> or <NUM> around which the plastics material of the support helix <NUM> or <NUM>, respectively, is extruded may be tensioned, either by tensioner(s) <NUM> incorporated acting on the spool(s) <NUM> from which each of the heating wires <NUM> or <NUM> are unwound, or with tensioner(s) <NUM> acting on the heating wires <NUM> or <NUM> at location(s) interposed between the spool(s) <NUM> and the extruder 107b. This application of tension on the heating wires <NUM> or <NUM> ahead of the extruder 107b causes a "drawing down" of each of the heating wires <NUM> or <NUM> through portions of the material of the support helix <NUM> or <NUM>, and closer towards the wall <NUM> or <NUM> as the hoses <NUM> or <NUM>, respectively, are made. Stated differently, when the flexible material of each of the support helix <NUM> or <NUM> is extruded around the heating wires <NUM> or <NUM> that are to be embedded therein, the heating wires <NUM> or <NUM> may initially centered within the extruded plastics material. However, as the freshly extruded (and still somewhat molten and compliant) plastics material of the support helix <NUM> or <NUM> is wound about the set of rotating rods <NUM> of hose making apparatus <NUM>, the tensioner(s) <NUM> may exert tension on the heating wires <NUM> or <NUM> to cause the heating wires <NUM> or <NUM> to be pulled radially inwardly toward the central axis <NUM> of the hose <NUM> or <NUM> being formed. This may cause the heating wires <NUM> or <NUM> to migrate within the flexible plastics material of the support helix <NUM> or <NUM> (again, while still somewhat molten and compliant) to a position within that plastics material that is closer to the interior of the hose <NUM> or <NUM>, respectively, being formed than their initially centered position.

As depicted most clearly in <FIG> and <FIG>, at least as part of enabling such use of tension to position the heating wires <NUM> or <NUM> as desired within the cross-section of the plastics material of the support helix <NUM> or <NUM>, a particular portion of the external surface of the support helix <NUM> or <NUM> may be specifically selected to be designated as a bonding surface <NUM> or <NUM>, respectively, that is to be put into contact with and bonded to a portion of the external surface of the wall <NUM> or <NUM> of the hose <NUM> or <NUM> that is designated as the corresponding bonding surface <NUM> or <NUM>. Thus, as the support helix <NUM> or <NUM> is spirally wrapped around the external surface of the wall <NUM> or <NUM>, it is these designated bonding surfaces <NUM> and <NUM>, or <NUM> and <NUM>, of each that are brought into contact with each other and bonded to each other.

Turning more specifically to <FIG>, as depicted, the portion of the external surface of the support helix <NUM> or <NUM> that is selected to be bonding surface <NUM> or <NUM>, respectively, may be specifically shaped and/or otherwise specifically configured for being bonded to the corresponding bonding surface <NUM> or <NUM> of the hose <NUM> or <NUM>, respectively. By way of example, and as specifically depicted, the bonding surface <NUM> or <NUM> may be formed to be a flat surface to accommodate the similarly flat configuration of the bonding support surface <NUM> or <NUM>, respectively. Alternatively, and also by way of example (though not specifically depicted), the bonding surface <NUM> or <NUM> may be formed to define a surface of convex or concave configuration to accommodate a corresponding concave or convex, respectively, configuration of the bonding surface <NUM> or <NUM>, respectively.

Alternatively or additionally, and as also depicted, the cross-section of the length of extruded material from which the wall <NUM> or <NUM> is formed may additionally include a pair of radially outwardly projecting guides <NUM> or <NUM>, respectively, to aid in guiding the bonding surface <NUM> or <NUM> of the support helix <NUM> or <NUM> into contact with the corresponding bonding surface <NUM> or <NUM> of the wall <NUM> or <NUM>, respectively. As also depicted, such guides <NUM> or <NUM> may define additional bonding surfaces <NUM> or <NUM>, respectively, that are meant to come into contact with, and to become bonded to, corresponding additional bonding surfaces <NUM> or <NUM> formed on the exterior surface of the support helix <NUM> or <NUM>, respectively. Thus, as the support helix <NUM> or <NUM> is spirally wrapped around the external surface of the wall <NUM> or <NUM>, there may be multiple corresponding pairs of bonding surfaces <NUM> and <NUM>, or <NUM> and <NUM>, that are brought into contact with each other and bonded to each other.

Turning more specifically to <FIG>, and regardless of whether such guide projections are provided, following the laying down of the support helix <NUM> or <NUM> onto the external surface of the wall <NUM> or <NUM> such that the bonding surfaces <NUM> and <NUM>, or <NUM> and <NUM> are put into contact with and bonded to each other, the aforedescribed tension causes inward migration of the heating wires <NUM> or <NUM> within the flexible (and still somewhat molten and compliant) plastics material of the support helix <NUM> or <NUM> toward the wall <NUM> or <NUM> (which may be less molten or no longer molten, and which may be used to stop the migration at the external surface of the wall <NUM> or <NUM>), toward the interior of the hose <NUM> or <NUM>, and toward the central axis <NUM> of the hose <NUM> or <NUM>, respectively.

This technique of causing a radially inward draw down may be deemed preferable to attempting to position the heating wires <NUM> or <NUM> within the cross-sections of the extrusions of the helixes <NUM> or <NUM> at such locations during extrusion. This technique of causing a radially inward draw down may also provide the flexibility to allow variations in placement of the heating wires <NUM> or <NUM> further radially inward and/or further radially outward within the cross-sections of the helixes <NUM> or <NUM>, respectively, as part of creating different variants of the hoses <NUM> or <NUM> that may have different heating characteristics (and/or other characteristics that may be influenced by placement of the heating wires <NUM> or <NUM> within the helixes <NUM> or <NUM>, respectively).

<FIG> through <NUM>, taken together, depict various aspects of an alternate embodiment of a process for making the inspiratory hose <NUM> and/or the expiratory hose <NUM>, including aspects of forming the support helixes <NUM> and/or <NUM> thereof to include one or more electrical wires <NUM> and/or <NUM>, respectively. As with <FIG>, it should be noted that, although the helixes <NUM> and <NUM> are depicted as each incorporating a pair of heating wires <NUM> and <NUM>, respectively, other embodiments of the hoses <NUM> and/or <NUM> are possible in which different numbers of electrical wires (whether heating wires, or other varieties of electrical wires) may be incorporated into the support helixes <NUM> and/or <NUM>, respectively, as well as other embodiments in which there may be multiple helixes that each carry one or more different electrical wires (again, whether heating wires, or not).

As in the embodiment of a hose making process of <FIG>, in the alternate embodiment of a hose making process of <FIG>, each of the hoses <NUM> and/or <NUM> may be formed using a modified variant of a typical hose manufacturing apparatus such as the hose manufacturing apparatus <NUM> introduced above in connection with <FIG>. However, while the final position of the electrical wires <NUM> or <NUM> within the support helix <NUM> or <NUM> is set while the hose <NUM> or <NUM> is formed on the hose manufacturing apparatus <NUM> in the process of <FIG>, in the alternate embodiment of <FIG>, the final position of the electrical wires <NUM> or <NUM> within the support helix <NUM> or <NUM> is set prior to the support helix <NUM> or <NUM> being introduced at the hose manufacturing apparatus <NUM>.

Turning to <FIG>, one or more spools <NUM> of the electrical wires <NUM> or <NUM> may be fed to the extruder 107b to enable a bead of plastics material to be extruded therearound as the electrical wires <NUM> or <NUM> are fed therethrough. The resulting newly formed bead of plastics material, which will become the support helix <NUM> or <NUM> of a hose <NUM> or <NUM>, may then be fed through a cooling device <NUM> to be cooled sufficiently to cause the plastics material to be hardened enough to prevent the electrical wires <NUM> or <NUM>, respectively, from migrating within the plastics material.

In some embodiments, the cooling device <NUM> may be a trough or other elongate container of water or other liquid through which the newly formed bead of support helix <NUM> or <NUM> is routed. In some of such embodiments, the water or other liquid may be maintained by exposure to the surrounding environment at an ambient room temperature that is far below the temperature at which the newly formed bead of support helix <NUM> or <NUM> emerges from the extruder 107b, where such an ambient room temperature is sufficiently cool as to cause sufficient hardening of the plastics material. However, in others of such embodiments, the water or other liquid may be actively cooled to a still lower temperature where such a lower temperature is deemed necessary to cause sufficient hardening of the plastics material. The temperature of the water or other liquid may be based, at least in part, on the rate at which the newly formed bead of support helix <NUM> or <NUM> is routed through the cooling device <NUM> so as to ensure that sufficient cooling is able to take place, while at the same time, avoiding excessive cooling such that the plastics material is caused to respond by hardening and/or contracting in size sufficiently quickly as to cause cracking or other undesirable changes thereto.

Following such cooling, and with the positions of the wires <NUM> or <NUM> thereby set within the plastics material of the newly formed and cooled bead of support helix <NUM> or <NUM> now set, the newly formed bead of support helix <NUM> or <NUM> may either be immediately used in making a hose <NUM> or <NUM>, respectively, or may be temporarily stored in preparation for making a hose <NUM> or <NUM> at a later time. More specifically, and as depicted, the newly formed bead of support helix <NUM> or <NUM> may be wound about another spool <NUM> in preparation for storage.

It may be deemed desirable to store multiple rolls of differing types of support helix <NUM> or <NUM>, whether on spools <NUM> or in some other manner of storage, so as to have a selection of differing types of support helix <NUM> or <NUM> available to enable a form of just-in-time
manufacturing of a hose <NUM> or <NUM> with a dynamically selected type of support helix <NUM> or <NUM>. This may obviate the need to, instead, store a variety of types of hose <NUM> or <NUM> that may be differentiated solely by the type of support helix <NUM> or <NUM> that is incorporated therein.

When the need arises to make a particular type hose <NUM> or <NUM> that includes a particular type of support helix <NUM> or <NUM>, respectively, a roll of that particular type of support helix <NUM> or <NUM> may then be retrieved and brought to a modified variant of the hose manufacturing apparatus <NUM> to be used in making the needed hose <NUM> or <NUM>.

Turning to <FIG>, the modifications that may be made to the hose manufacturing apparatus <NUM> may include the addition of a heating device <NUM> to re-heat a support helix <NUM> or <NUM> as it is supplied to the hose manufacturing apparatus <NUM> as part of manufacturing a hose <NUM> or <NUM>, respectively. As the bead of support helix <NUM> or <NUM> is fed through the heating device <NUM>, it is re-heated to a controlled degree that causes outer surface portions of the plastics material thereof (e.g., the bonding surface <NUM> or <NUM>) to slightly molten such that those outer surface portions are softened and become tacky. The degree of re-heating may be controlled to avoid overheating to such an extent that inner portions of the plastics material of the bead of support helix <NUM> or <NUM> in the vicinity of the electrical wires <NUM> or <NUM>, respectively, become molten such that the electrical wires <NUM> or <NUM> are then able to migrate to new positions within that plastics material. By making outer surface portions of the plastics material of the bead of support helix <NUM> or <NUM> tacky (e.g., the bonding surface <NUM> or <NUM>), the now re-heated bead is caused to readily bond to the exterior of the wall <NUM> or <NUM> of the hose <NUM> or <NUM> that is being formed from the web of plastics material freshly extruded by the extruder 107a (e.g., the bonding surfaces <NUM> and <NUM>, or <NUM> and <NUM>, are caused to readily bond). Such softening of outer surface portions of the bead of support helix <NUM> or <NUM> also serves to make the bead less resistant to being wrapped around the exterior of the wall <NUM> or <NUM> of the hose <NUM> or <NUM>, respectively, that is being formed with the hose manufacturing apparatus <NUM>. More specifically, such softening of outer surface portions serves to make the bead of support helix <NUM> or <NUM> less resistant to being bent into the particular radius of curve needed for it to be wrapped around the exterior of the wall <NUM> or <NUM> of the hose <NUM> or <NUM>, respectively, that is being so formed. In this way, the separately formed bead of support helix <NUM> or <NUM> becomes the support helix <NUM> or <NUM> of the hose <NUM> or <NUM>, as depicted in <FIG>, thereby completing the formation thereof.

Turning to both <FIG> and <FIG>, as an alternative to storing the bead of support helix <NUM> or <NUM> after it has been formed using the extruder 107b and then cooled by the cooling device <NUM>, the newly formed bead of support helix <NUM> or <NUM> may be immediately and directly fed to the heating device <NUM> to have exterior portions of the plastics material thereof (e.g., the bonding surface <NUM> or <NUM>) re-heated as has just been described. In this case, and as indicated by the depicted spool <NUM> being drawing with dotted lines, the winding of the newly formed and cooled bead of support helix <NUM> or <NUM> onto the depicted spool <NUM>, and the subsequent unwinding therefrom, may be entirely obviated. Instead, the extruder 107b and the cooling device <NUM> may be located in the vicinity of the hose manufacturing apparatus <NUM>, along with the heating device <NUM>.

Turning to <FIG>, regardless of whether the bead of support helix <NUM> or <NUM> formed as depicted in <FIG> is used immediately in forming a hose <NUM> or <NUM>, or is stored for later use in forming a hose <NUM> or <NUM> at a later time, in some embodiments, the heating device <NUM> may employ air that has been heated to a controlled degree in re-heating the bead of the support helix <NUM> or <NUM> at whatever time it is brought to the hose manufacturing apparatus <NUM> to form a hose <NUM> or <NUM>, respectively. More specifically, the heating device <NUM> may include a heating tube <NUM> through which the bead of support helix <NUM> or <NUM> is fed on the way to being provided to the hose manufacturing apparatus <NUM>, and into which the hot air is blown to heat the support helix <NUM> or <NUM> as it passes therethrough. The heating device <NUM> may include a blower <NUM> to pull in surrounding ambient air, and may include a heater <NUM> to heat that ambient air as it is blown through the heater <NUM> and into the heating tube <NUM> by the blower <NUM>.

The temperature and/or volume of the hot air blown into the heating tube <NUM> may be adjusted to control the degree to which outer surface portions of the bead of support helix <NUM> or <NUM> are caused to become molten. Such parameters as the inner diameter and/or length of the heating tube <NUM>, and/or the temperature and/or volume of the hot air blown into the heating tube <NUM> may be based on such factors as the cross-section of the bead of support helix <NUM> or <NUM>, and/or the speed at which the bead is fed through the heating tube. The speed at which the bead of support helix <NUM> or <NUM> is fed through the heating tube <NUM> may be entirely controlled by the speed at which bead is to be fed to the hose manufacturing apparatus <NUM> to form a hose <NUM> or <NUM>, respectively.

It has been found that the shape of the cross-section of the heating tube <NUM> need not match the shape of the cross-section of the particular bead of support helix <NUM> or <NUM> that is fed therethrough. It has also been found that the inner diameter of the heating tube <NUM> need not be selected to closely surround the outer surface portions of the bead of support helix <NUM> or <NUM> that is fed therethrough. This enables the use of a heating tube <NUM> that has a relatively simple, generally round cross-section with an inner diameter that may be large enough to accommodate a relatively wide variety of beads of support helix <NUM> or <NUM> of a wide variety of cross-sectional shapes and sizes.

To aid in providing relatively even re-heating of outer surface portions of a bead of support helix <NUM> or <NUM> fed through the heating tube <NUM>, the heating tube <NUM> may be shaped and/or sized, and/or the location within the heating tube <NUM> at which the hot air enters may be shaped and/or sized, to cause one or more spiraling vortices of hot air to be formed within the heating tube <NUM> that may serve to urge the support helix <NUM> or <NUM> to tend to remain centered within the heating tube <NUM> as it passes therethrough to better enable exposure of the entirety of the outer surface thereof to the hot air.

The lack of need to employ differing heating tubes <NUM> of differing cross-sectional shapes and/or differing diameters to accommodate a wide variety of types of support helix <NUM> or <NUM> may enable a single hose manufacturing apparatus <NUM> that has been modified with at least the addition of the heating device <NUM> to be more easily used in making a wide variety of different types of the hoses <NUM> or <NUM> employing a wide variety of different types of the support helixes <NUM> or <NUM>. Specifically, the heating device <NUM> and/or the heating tube <NUM> becomes a component thereof that need not be physically swapped or otherwise physically altered when transitioning from making one type of hose <NUM> or <NUM> with a support helix <NUM> or <NUM> having one cross-section to making another type of hose <NUM> or <NUM> with another support helix <NUM> or <NUM> having a different cross-section, beyond possibly needing to reposition the heating device <NUM> to accommodate such other differences as differences in the diameters of the two types of hose <NUM> or <NUM>, respectively.

Further, the lack of need to in some way match a particular shape and/or diameter of the heating tube <NUM> with a particular shape and/or diameter of cross-section of a support helix <NUM> or <NUM>, along with the ability to provide relatively even re-heating of outer surface portions of a support helix <NUM> or <NUM>, also obviates the need to in some way align the orientation of the heating tube <NUM> and/or the direction from which hot air enters the heating tube <NUM> in some particular way to the orientation of the cross-section of a support helix <NUM> or <NUM>. Stated differently, the direction in which a bonding surface <NUM> or <NUM> of a support helix <NUM> or <NUM> is facing as it passes through the heating tube <NUM> can be entirely ignored such that heating tube <NUM> need not be rotated to cause the direction from which hot air enters the heating tube <NUM> to be oriented in a particular manner relative to the direction in which the that bonding surface <NUM> or <NUM> faces. This may obviate the need to in any way reposition the heating tube <NUM> relative to other components of the manufacturing apparatus <NUM>, except possibly where there is a change in the diameter of the hose <NUM> or <NUM> to be made.

Thus, and turning briefly to <FIG>, it is not necessary to orient a support helix <NUM> or <NUM> as it is routed through the heating tube <NUM> to cause a bonding surface <NUM> or <NUM> thereof to directly face the oncoming flow of hot air entering the heating tube <NUM>, or to cause the bonding surface <NUM> or <NUM>, respectively, to face in any other particular direction relative to that hot air flow. And therefore, the support helix <NUM> or <NUM> may be oriented in any direction within the heating tube <NUM>, such as in the orientation depicted in <FIG> in which the bonding surface <NUM> or <NUM>, respectively, is not caused to face directly into the oncoming flow of hot air into the heating tube <NUM>, or to face <NUM> degrees away from that hot air flow, or to face in any other particular direction relatively to that hot air flow.

Still further, the same lack of need to in some way match a particular shape and/or diameter of the heating tube <NUM> with a particular shape and/or diameter of cross-section of a support helix <NUM> or <NUM>, along with the ability to provide relatively even re-heating of outer surface portions of a support helix <NUM> or <NUM>, also serves to enable the re-heating of types of support helix <NUM> or <NUM> that may not have a specific portion of the exterior thereof that is designated to serve as a bonding surface <NUM> or <NUM>, respectively. Such a circumstance may arise, for example, where a support helix <NUM> or <NUM> is used that has a circular cross-section or other cross-section that does not define a distinct portion of its exterior that may be shaped to in some particular way correspond to the shape of a particular portion of the exterior of the wall <NUM> or <NUM> of a hose <NUM> or <NUM>, respectively. Such a circumstance may also arise, for example, where a support helix <NUM> or <NUM> is used that has an irregularly- shaped cross-section and/or a cross-section that frequently changes along its length.

However, in embodiments in which a support helix <NUM> or <NUM> is used that has a cross-section that does define a distinct bonding surface <NUM> or <NUM>, respectively, it may be deemed desirable to use a different embodiment of the heating device <NUM> that is configured to avoid re heating the entirety of the exterior of the support helix <NUM> or <NUM>. More specifically, it may be deemed desirable to limit the re-heating of a support helix <NUM> or <NUM> to just the bonding surface <NUM> or <NUM> to the extent needed to cause the bonding surface <NUM> or <NUM> to become molten, while avoiding (at least to the extent possible) re-heating other portions of the exterior of the support helix <NUM> or <NUM> (e.g., avoiding heating at least a portion of the exterior that is on a side of the exterior that is opposite the side that includes the support helix <NUM> or <NUM>).

<FIG> provides a block diagram of an alternate embodiment of the heating device <NUM> (along with a cross-section of an example support helix <NUM> or <NUM>, similar to <FIG>) that enables such selective heating of the bonding surface <NUM> or <NUM> of a support helix <NUM> or <NUM>. As depicted, such an alternate embodiment of the heating device <NUM> may be similar to the embodiment of <FIG> and <FIG>, but with the substantial difference of not including the heating tube <NUM>. Thus, unlike the embodiment of the heating device <NUM> of <FIG> and <FIG>, in the alternate embodiment of <FIG>, there may be no component thereof that serves to in any way direct the flow of hot air that is produced by the combination of the blower <NUM> and the heater <NUM> fully around the cross-section of a support helix <NUM> or <NUM>. Thus, also unlike the embodiment of the heating device <NUM> of <FIG> and <FIG>, in the alternate embodiment of <FIG>, the support helix <NUM> or <NUM> must be routed past this alternate embodiment of the heating device <NUM> in a position and orientation relative thereto that causes the bonding surface <NUM> and <NUM> to face into the output hot air flow so as to enable such selective re-heating of the bonding surface <NUM> or <NUM>.

The temperature and/or volume of the hot air output by the alternate embodiment of the heating device <NUM> of <FIG> may be adjusted to control the degree to which the bonding surface <NUM> or <NUM> is caused to become molten. Such parameters as the temperature and/or volume of the hot air may be based on such factors as the shape and/or size of the cross-section of the bead of support helix <NUM> or <NUM>, the shape and/or size of the bonding surface <NUM> or <NUM>, the quantity and/or size of any wires within the support helix <NUM> or <NUM>, and/or the speed at which the bead is fed past the heating device <NUM>. The speed at which the bead of the support helix <NUM> or <NUM> is fed past the heating device <NUM> may be entirely controlled by the speed at which bead is to be fed to the hose manufacturing apparatus <NUM> to form a hose <NUM> or <NUM>, respectively.

<FIG> provides a block diagram of another alternate embodiment of the heating device <NUM> (also along with a cross-section of an example support helix <NUM> or <NUM>, similar to <FIG>) that enables such selective heating of the bonding surface <NUM> or <NUM> of a support helix <NUM> or <NUM>. As depicted, this other alternate embodiment of the heating device <NUM> may be similar to the embodiment of <FIG>, but with the substantial difference of including the blower <NUM> to create an air flow, and instead, relying upon solely the heater <NUM> to output radiant heat toward the bonding surface <NUM> or <NUM> of a support helix <NUM> or <NUM>. Thus, like the alternate embodiment of the heating device <NUM> of <FIG>, in this other alternate embodiment of <FIG>, the support helix <NUM> or <NUM> must also be routed past this alternate embodiment of the heating device <NUM> in at least a particular orientation to enable the bonding surface <NUM> or <NUM> to be re-heated. The temperature and/or level of energy of the radiant heat output by the alternate embodiment of the heating device <NUM> of <FIG> may be adjusted to control the degree to which the bonding surface <NUM> or <NUM> is caused to become molten. Such parameters as the temperature and/or level of energy of the radiant heat output may be based on such factors as the shape and/or size of the cross-section of the bead of support helix <NUM> or <NUM>, the shape and/or size of the bonding surface <NUM> or <NUM>, the quantity and/or size of any wires within the support helix <NUM> or <NUM>, the speed at which the bead is fed past the heating device <NUM>, and/or the distance from the heating device <NUM> at which the bead is fed past the heating device <NUM>. The speed at which the bead of the support helix <NUM> or <NUM> is fed past the heating device <NUM> may be entirely controlled by the speed at which bead is to be fed to the hose manufacturing apparatus <NUM> to form a hose <NUM> or <NUM>, respectively.

Referring to both of the alternate embodiments of the heating device <NUM> of <FIG>, as the bead of support helix <NUM> or <NUM> is fed past either of these alternate embodiments of the heating device <NUM>, the bonding surface <NUM> or <NUM> is re-heated to a controlled degree that causes the plastics material thereof to become slightly molten such that the bonding surface <NUM> or <NUM>, respectively, are softened and become tacky. The degree of re-heating may be controlled to avoid overheating to such an extent that inner portions of the plastics material of the bead of support helix <NUM> or <NUM> in the vicinity of the electrical wires <NUM> or <NUM>, respectively, become molten such that the electrical wires <NUM> or <NUM> are then able to migrate to new positions within that plastics material. By making the plastics material of the bonding surface <NUM> or <NUM> tacky, the now re-heated bonding surface <NUM> or <NUM> is caused to readily bond to the exterior of the wall <NUM> or <NUM> of the hose <NUM> or <NUM> that is being formed from the web of plastics material freshly extruded by the extruder 107a (e.g., the bonding surfaces <NUM> and <NUM>, or <NUM> and <NUM>, are caused to readily bond).

Turning to FIGURE <NUM>, an advantage that may be afforded by limiting (to the extent possible) the re-heating of the exterior of a support helix <NUM> or <NUM> to the bonding surface <NUM> or <NUM> may be that the plastics material that forms the bonding surface <NUM> or <NUM> (and extending into the plastics material of the support helix <NUM> or <NUM> to a relatively limited depth from the bonding surface <NUM> or <NUM> that is not deep enough to extend to any wires positioned therein) may become molten to an extent that enables the plastics material within the side of the support helix <NUM> or <NUM> that includes the bonding surface <NUM> or <NUM> to be more easily compressed as part of becoming more easily bendable so as to be more pliable for following the curvature of the exterior of the wall <NUM> or <NUM> of a hose <NUM> and <NUM> as the bonding surface <NUM> or <NUM> is put into contact with the exterior of the wall <NUM> or <NUM>, respectively. By allowing at least the portion of the exterior of the support helix <NUM> or <NUM> that is on the side thereof that is opposite of the bonding surface <NUM> or <NUM> to remain in an un-mo Iten state, at least that portion on that side may serve to resist allowing the support helix <NUM> or <NUM> to become distorted in its dimensions in other ways, such as being flattened against the wall <NUM> or <NUM> such that the ability of the support helix <NUM> or <NUM> to serve its function as a physical support of the hose <NUM> or <NUM> is compromised.

Alternatively or additionally, an advantage that may be afforded by limiting (to the extent possible) the re-heating of the exterior of a support helix <NUM> or <NUM> to the bonding surface <NUM> or <NUM> may be that the portion of the exterior of the support helix <NUM> or <NUM> that is caused to become tacky as a result of becoming molten may be largely or entirely limited to the bonding surface <NUM> or <NUM>. In this way other portions of the exterior of the support helix <NUM> or <NUM> are allowed to remain in an un-mo Iten state such that they do not become tacky, which may make handling the support helix <NUM> or <NUM> (especially where it is being unwound from a spool <NUM> as depicted in <FIG>) considerably easier.

<FIG> depict cross-sections of an example assortment of types of support helix <NUM> or <NUM> that may be dynamically selected for use in making a hose <NUM> or <NUM>, respectively. As so depicted, these widely differing types of support helix <NUM> or <NUM> may differ in shape and/or size of the cross-section of their plastics material, as well as in the quantity, size (e.g., gauge measurement), and/or arrangement of electrical wires <NUM> or <NUM> therein.

<FIG> depict the cross-sections of two example embodiments of support helix <NUM> or <NUM> that have a similar cross-section of plastics material that may be said to resemble a slice of a loaf of bread. However, as also depicted, the quantities of electrical wires <NUM> or <NUM> incorporated therein differs between these two example embodiments.

<FIG>, <FIG> depict the cross-sections of four example embodiments of support helix <NUM> or <NUM> that have a similar "mushroom" cross-section of plastics material.

Again, as depicted by <FIG>, differing quantities of electrical wires <NUM> or <NUM> may be incorporated into the same cross-section of the plastics material in different ones of these example embodiments, and in differing arrangements therein. However, <FIG> also specifically depict that electrical wires <NUM> or <NUM> of differing size (e.g., differing gauges) may also be incorporated into the same cross-section of plastics material in different ones of these example embodiments.

<FIG> depict the cross-sections of two example embodiments of support helix <NUM> or <NUM> that have generally similar elliptical cross-sections of plastics material.

However, as also depicted, such cross-sections of plastics material may still differ slightly in such details as the elliptical cross-section depicted in <FIG> having a flattened portion of its outer surface (which may enhance bonding to the outer surface of the wall <NUM> or <NUM>), whereas the cross-section depicted in <FIG> does not. Again, and as also depicted, the quantities of electrical wires <NUM> or <NUM> incorporated therein differs between these two example embodiments.

FIGURES <NUM>, <FIG> and <FIG> depict the cross-sections of three example embodiments of support helix <NUM> or <NUM> that have generally similar rectangular cross-sections of plastics material.

However, as also depicted, such cross-sections of plastics material may still differ slightly in their dimensions and/or in their ratios between height and width. As also depicted, even though these different embodiments all incorporate the same quantity and/or size of electrical wires <NUM> or <NUM>, they may differ in the placement of those electrical wires <NUM> or <NUM> among these three example embodiments.

<FIG> depicts a cross-section of an example embodiment of support helix <NUM> or <NUM> that has a generally triangular cross-section of plastics material.

<FIG>, taken together, depict various aspects of coupling the expiratory inlet fitting <NUM> to an undermold coupling <NUM>, and thereby, to one end of the expiratory hose <NUM>. Stated differently, and as earlier depicted in the exploded perspective views in each of FIGURES ID, IE and 3A, the expiratory inlet fitting <NUM> may be coupled to one end of the expiratory hose <NUM> via the depicted undermold coupling <NUM> interposed between a portion of the outer surface of that end of the expiratory hose <NUM> and a portion of the inner surface of a hose interface <NUM> of the expiratory inlet fitting <NUM>.

The undermold coupling <NUM> may include a tubular portion <NUM> having a cylindrical tubular shape that defines a passage therethrough. At one end of the tubular shape of the tubular portion <NUM> may be a ring <NUM> that extends radially outward from the cylindrical tubular shape of the tubular portion <NUM>. Extending from the ring <NUM> (or form another portion of the external surface of the tubular portion <NUM>) may be one or more gratings <NUM> that may be defined by one or more parallel elongate portions of the flexible plastics material of the undermold coupling <NUM> that define one or more parallel slots <NUM>. Each of the elongate portions of the material that define one of the one or more gratings <NUM> may be curved to allow each to extend in a manner that follows the curve of the cylindrical shape of the tubular portion <NUM>.

Each grating <NUM> may be supported by, and attached to, the rest of the structure of the undermold coupling <NUM> (e.g., connected to the ring portion <NUM>, as depicted) by a pair of grating supports <NUM> that may cooperate with the grating <NUM> to create what may visually resemble a ladder. The grating supports may tend to support the one or more gratings <NUM> at a location and in an orientation that causes each grating <NUM> to extend alongside and in parallel with a portion of the external surface of the tubular portion <NUM>. While each grating <NUM> is so positioned by one or more of the grating supports <NUM>, inwardly facing surfaces <NUM> of each of the one or more curved elongate portions of flexible plastics material that defines each of the gratings <NUM> may tend to be positioned in contact with the portion of the external surface of the tubular portion <NUM> that its corresponding grating <NUM> overlies. Being formed of the flexible plastics material of the undermold coupling <NUM>, the grating supports <NUM> may each be flexible enough to allow each of the gratings <NUM> to be pulled away from its position extending alongside and parallel with a portion of the external surface of the tubular portion <NUM> (thereby pulling the inwardly facing surfaces thereof out of contact with the external surface of the tubular portion <NUM>.

The hose interface of the expiratory inlet fitting <NUM> may incorporate one or more gratings <NUM> that are meant to correspond to the one or more gratings <NUM> carried by the undermold coupling <NUM>. Each of the one or more gratings <NUM> may be defined by one or more parallel elongate portions of the rigid plastics material of the expiratory inlet fitting <NUM> that define one or more parallel slots <NUM> that may have the appearance of a set of one or more vent slots formed through the wall of the expiratory inlet fitting <NUM>. Each of the elongate portions of the material that define one of the one or more gratings <NUM> may be curved to allow each to extend in a manner that parallels the curve of the cylindrical shape of the tubular portion <NUM>. Additionally, the one or more parallel elongate portions of the material of the expiratory fitting <NUM> that define one of the one or more gratings <NUM>, and the one or more slots <NUM> defined thereby, may be intersected by one or more troughs <NUM> formed in the cylindrical external surface of the expiratory inlet fitting <NUM> to receive a corresponding one or more of the grating supports <NUM>. As depicted most clearly in <FIG>, <FIG>, <FIG> and <FIG>, the undermold coupling <NUM> may include threads <NUM> formed on the inner surface of the tubular portion <NUM> to receive and surround the external surface of one end of the expiratory hose <NUM> in a manner that engages the wall <NUM> and the support helix <NUM> thereof as if the wall <NUM> and helix <NUM>, together, formed matching threads as a mechanism by which the undermold coupling <NUM> may grip that end of expiratory hose <NUM> within the tubular portion <NUM>.

In some embodiments, the tubular portion <NUM> of the undermold coupling <NUM> may be threaded onto an end of the expiratory hose <NUM>.

Turning more specifically to <FIG> and <FIG>, with the undermold coupling <NUM> so threaded onto an end of the expiratory hose <NUM>, that end of the expiratory hose <NUM> may be inserted into the hose interface <NUM> of the expiratory inlet fitting <NUM>. As a result, the tubular portion <NUM> of undermold coupling <NUM> is inserted into the hose interface <NUM> and becomes interposed between the external surface of that end of the expiratory hose <NUM> and the internal surface of the hose interface <NUM> of the expiratory inlet fitting <NUM>. As depicted in most clearly in <FIG> and <FIG>, as such insertion occurs, each grating <NUM> of the undermold coupling <NUM> may be pulled away from the tubular portion <NUM> (relying on the flexibility of the grating supports <NUM> to act somewhat like hinges) and caused to extend over exterior portions of the expiration inlet fitting <NUM> in the vicinity of the hose interface <NUM>. With each grating <NUM> so positioned over its corresponding grating <NUM>, the grating <NUM> may then be allowed to return to a position alongside and parallel to the external surface of the tubular portion <NUM> of the undermold coupling <NUM>.

As depicted most clearly in <FIG>, with the each of the gratings <NUM> allowed to return to a position alongside and parallel to the external surface of the tubular portion <NUM> while each of the gratings <NUM> is positioned over its corresponding grating <NUM>, the corresponding ones of the one or more gratings <NUM> and <NUM> are caused to intermesh in a manner that mechanically locks the undermold coupling <NUM> within the hose interface <NUM>. More specifically, in each such interlock between a corresponding pair of gratings <NUM> and <NUM>, each of the elongate portions of a grating <NUM> of the undermold coupling <NUM> extends into a corresponding slot <NUM> defined by the corresponding grating <NUM> of the expiratory inlet fitting <NUM>, and each of the elongate portions of that corresponding grating <NUM> extends into a corresponding slot <NUM> defined by the grating <NUM>. As a result, the inwardly facing surfaces <NUM> of each of the one or more curved elongate portions of the flexible plastics material of the undermold coupling that define each of the gratings <NUM> is allowed to be brought back into contact with a portion of the external surface of the tubular portion <NUM>, as most clearly depicted in <FIG>. With such surface contacts once again made, while the one or more corresponding pairs of the gratings <NUM> and <NUM> are so intermeshed, heat may be applied to soften at least the undermold coupling <NUM> to cause the inwardly facing surfaces <NUM> of those portions of the one or more gratings <NUM> that are once again in contact with the external surface of the tubular portion <NUM> to become bonded to the exterior of the tubular portion <NUM>, as most clearly depicted in <FIG>. Such heating may also more broadly bond the materials of the thread-like exterior of the end of the expiratory hose <NUM> (onto which the undermold coupling <NUM> is threaded) to surfaces of the threads <NUM> formed within the undermold coupling <NUM>, and such heating may also more broadly bond the material of the exterior surface of the tubular portion <NUM> of the undermold coupling <NUM> to the interior surface of the expiration inlet fitting <NUM> into which the undermold coupling <NUM> is inserted. As a result, gas-tight seals may be formed among these components.

In other embodiments, an end of the expiratory hose <NUM> may be inserted into the hose interface <NUM> of the expiratory inlet fitting <NUM> without an undermold coupling <NUM> threaded thereon. After such insertion, the flexible material of the undermold coupling <NUM>, in molten form, may be injected into one or more of the slots <NUM> of one or more gratings <NUM> of the hose interface <NUM> to fill the space between the thread-like external surface of that end of the expiratory hose <NUM> and the interior surface of the hose interface <NUM> to form the undermold coupling <NUM> in place therebetween, as well as to fill each of the slots <NUM>. Alternatively, the flexible material of the undermold coupling <NUM>, in molten form, may be injected therein between the expiratory hose <NUM> and the edge of the interior surface of the hose interface <NUM>, where the expiratory hose <NUM> enters into the hose interface <NUM>, to form the undermold coupling <NUM> in place, as well as to fill each of the slots <NUM> from within the interior of the hose interface <NUM>. Regardless of the exact manner in which the molten form of the material of the undermold coupling <NUM> is injected to form the undermold coupling <NUM> in place, in so forming the undermold coupling <NUM> in place, the molten form of the undermold coupling <NUM> may bond to the materials of thread-like external surface at the end of the expiratory hose <NUM> and the interior surface of the hose interface <NUM> to form a gas-tight seal therebetween. It should be noted that although <FIG> through <FIG> depict these features in a manner that is focused on the connection of an end of the expiratory hose <NUM> to the expiratory inlet fitting <NUM>, the very same coupling arrangement just described may be employed to couple the other end of the expiratory hose <NUM> to the expiratory outlet fitting <NUM>, and/or one or both ends of the inspiratory hose <NUM> to one or both of the inspiratory inlet fitting <NUM> and the inspiratory outlet fitting <NUM>. Stated differently, and as depicted most clearly in each of FIGURES ID, IE and 3A, multiple ones of the undermold coupling <NUM> may be employed to couple each of the fittings <NUM> and <NUM> to opposite ends of the inspiratory hose <NUM>, and to couple each of the fittings <NUM> and <NUM> to opposite ends of the expiratory hose <NUM>.

<FIG>, taken together, depict various aspects of incorporating the plug <NUM> or <NUM> incorporating the electrical connector <NUM> or <NUM> into one of the three connections provided by the inspiratory inlet fitting <NUM> or the expiratory outlet fitting <NUM>, respectively.

Also depicted are various aspects of the direct electrical coupling of the heating wires <NUM> or <NUM> to the electrical connector <NUM> or <NUM>, respectively.

Each of <FIG> and <FIG> depicts a subset of the components of the inspiratory hose assembly <NUM> toward the end thereof that is to be connected to the medical device <NUM>.

More precisely, <FIG> and <FIG> each depict the path followed by the support helix <NUM> within the inspiratory hose <NUM> and where an end of the inspiratory hose <NUM> is coupled to the inspiratory inlet fitting <NUM>. The wall <NUM> of the inspiratory hose <NUM> has been omitted in both of these views for purposes of visual clarity. Additionally, in <FIG>, both the plug <NUM> and the insulating shroud portion of the electrical connector <NUM> have been omitted, also for purposes of visual clarity. As depicted, where an end of a portion of the inspiratory hose <NUM> is inserted into a portion of the inspiratory inlet fitting <NUM>, a relatively short portion of the support helix <NUM> is unwound from its helical path within the inspiratory hose <NUM> and is employed as an electrical cable to bring the heating wires <NUM> therein to the electrical connector <NUM> within the plug <NUM>.

More specifically, a relatively short portion of the support helix <NUM> is pulled out of the end of the inspiratory hose <NUM> (i.e., unwound therefrom) where that end is inserted into the inspiratory inlet fitting <NUM>, and straightened to at least some degree for use as an electrical cable to bring the heating wires <NUM> therein directly to the electrical connector <NUM>. This unwinding of the relatively short portion of the support helix <NUM> may be performed prior to the threading of the depicted undermold coupling <NUM> onto the end of the inspiratory hose <NUM> that is to be inserted into the inspiratory inlet fitting <NUM>. As a result, the relatively short unwound portion of the support helix <NUM> extends beyond the end of the inspiratory hose <NUM> onto which the undermold coupling <NUM> is threaded, thereby emerging from within the undermold coupling <NUM> and extending further into the interior of the inspiratory inlet fitting <NUM> than the end of the inspiratory hose <NUM> onto which the undermold coupling <NUM> is threaded.

The end of the relatively short portion of the support helix <NUM> that extends toward the electrical connector <NUM> may be partly stripped away to remove at least enough of the flexible plastics material of the support helix <NUM> to expose enough of the heating wires <NUM> therein to enable forming an electrical connection with the contacts <NUM> of the electrical connector <NUM>. More precisely, the plastics material of the support helix <NUM> may be stripped away in a manner that may be akin to procedures often used in preparing conventional multi-conductor cables for the connection of the individual wires therein to contacts of an electrical connector or other electrical device. Thus, typical wire stripping techniques may be employed to gain access to each of the heating wires <NUM>, and then the conductor <NUM> (see <FIG>) within each of the heating wires <NUM> may be soldered to a soldering tab of one of the electrical contacts <NUM> of the electrical connector <NUM>. Additionally, if the relatively short unwound portion of the support helix <NUM> is additionally covered in a sheath (e.g., heatshrink tubing that may be sleeved over the relatively short unwound portion of the support helix <NUM>), then part of that sheath may also be similarly stripped away using typical wire stripping techniques. As previously discussed, the conductor <NUM> of each of the heating wires <NUM> may be sheathed within an individual insulator <NUM> that is selected to be thermally resistant to the temperatures expected to be encountered during heating of the inspiratory hose <NUM>, but not to the temperatures expected to be encountered during soldering, thereby eliminating the need to strip each of the conductors <NUM> of their individual insulators <NUM> prior to soldering each of the conductors <NUM> to a soldering tab of one of the electrical contacts <NUM>.

In separating the relatively short portion of the support helix <NUM> from the inspiratory hose <NUM>, portions of the wall <NUM> (again, not shown for purposes of visual clarity) that extend between adjacent coils of the support helix <NUM> that are included in the relatively short portion thereof may be trimmed away. After being so separated, the relatively short unwound portion of the support helix <NUM> may be heated to soften the flexible plastics material thereof (i.e., to relax the molecules of the flexible plastics material thereof) to aid in straightening it out from its original helical path within the inspiratory hose <NUM> (i.e., causing the molecules of the flexible plastics material of the relatively short portion of the support helix <NUM> to adopt a straightened path as a new resting state).

The actual length of the relatively short portion of the support helix <NUM> that emerges from the undermold coupling <NUM> and extends further into the interior of the inspiration inlet fitting <NUM> may be based, at least in part, on the dimensions of the inspiration inlet fitting <NUM>. More specifically, the length may be selected based on the length needed to extend from the undermold coupling <NUM> and to the electrical connector <NUM>, and may include a predetermined additional length needed to allow manufacturing personnel sufficient physical access to solder the conductors <NUM> of the heating wires <NUM> to the soldering tabs of the electrical contacts <NUM>, as earlier described.

In a manner somewhat similar to <FIG> and <FIG>, <FIG> depicts a subset of the components of the expiratory hose assembly <NUM> toward the end thereof that is to be connected to the medical device <NUM>. More precisely, <FIG> depicts the path followed by the support helix <NUM> within the expiratory hose <NUM> and where an end of the expiratory hose <NUM> is coupled to the expiratory outlet fitting <NUM>. The wall <NUM> of the expiratory hose <NUM>, the plug <NUM> and the insulating shroud portion of the electrical connector <NUM> have all been omitted for purposes of visual clarity. As depicted, where an end of a portion of the expiratory hose <NUM> is inserted into a portion of the expiratory outlet fitting <NUM>, a relatively short portion of the support helix <NUM> is unwound from its helical path within the expiratory hose <NUM> and is employed as an electrical cable to bring the heating wires <NUM> therein to the electrical connector <NUM> within the plug <NUM> (again, not shown).

More specifically, a relatively short portion of the support helix <NUM> is pulled out of the end of the expiratory hose <NUM> (i.e., unwound therefrom) where that end is inserted into the expiratory outlet fitting <NUM>, and straightened to at least some degree for use as an electrical cable to bring the heating wires <NUM> therein directly to the electrical connector <NUM>. In a manner similar to what was discussed above concerning the support helix <NUM>, this unwinding of the relatively short portion of the support helix <NUM> may be performed prior to the threading of another of the undermold couplings <NUM> onto the end of the expiratory hose <NUM> that is to be inserted into the expiratory outlet fitting <NUM>. As a result, the relatively short portion of the support helix <NUM> extends beyond the end of the expiratory hose <NUM> onto which the undermold coupling <NUM> is threaded, thereby emerging from within the undermold coupling <NUM> and extending further into the interior of the expiratory outlet fitting <NUM> than the end of the expiratory hose <NUM> onto which the undermold coupling <NUM> is threaded.

As with the earlier discussed relatively short portion of the support helix <NUM> employed as an electrical cable, the end of the relatively short unwound portion of the support helix <NUM> that extends toward the electrical connector <NUM> may also be partly stripped away to remove at least enough of the flexible plastics material of the support helix <NUM> to expose enough of the heating wires <NUM> therein to enable forming an electrical connection with the contacts <NUM> of the electrical connector <NUM>. Again, this may also be done using typical wire stripping techniques, and again, if the stripped-away part of the unwound portion of the support helix <NUM> is
additionally covered in a sheath (e.g., heatshrink tubing), part of that sheath may also be similarly stripped away using typical wire stripping techniques. Also again, in separating the relatively short portion of the support helix <NUM> from the expiratory hose <NUM>, portions of the wall <NUM> (again, not shown for purposes of visual clarity) that extend between adjacent coils of the support helix <NUM> that are included in the relatively short portion thereof may be trimmed away. And again, after being so separated, the relatively short portion of the support helix <NUM> may be heated to soften the flexible plastics material thereof to aid in straightening it out from its original helical path within the expiratory hose <NUM>.

As with the earlier discussed relatively short portion of the support helix <NUM> employed as an electrical cable, the actual length of the relatively short portion of the support helix <NUM> that emerges from the undermold coupling <NUM> and extends further into the interior of the expiration outlet fitting <NUM> may be based, at least in part, on the dimensions of the expiration outlet fitting <NUM>. More specifically, the length may be selected based on the length needed to extend from the undermold coupling <NUM> and to the electrical connector <NUM>, and may include a predetermined additional length needed to allow manufacturing personnel sufficient physical access to solder the conductors <NUM> of the heating wires <NUM> to the soldering tabs of the electrical contacts <NUM>.

Such use of a portion of the support helixes <NUM> and/or <NUM>, as if each were a conventional two-conductor electric cable, advantageously avoids the creation of electrical terminations where a transition is made between the heating wires <NUM> and/or <NUM> of the support helixes <NUM> and/or <NUM> to non-heating wires that travel a relatively short distance within the fittings <NUM> and/or <NUM> to electrically couple the heating wires <NUM> and/or <NUM> to the electrical connectors <NUM> and/or <NUM>, respectively. Experience has shown that such electrical terminations to transition between heating and non-heating wires can be a source of potentially dangerous electrical failures. Poorly implemented electrical terminations of this type can actually have a higher resistance than the heating wires <NUM>, themselves, such that the terminations can become hotter than either the heating wires <NUM> or <NUM>. This may lead to such hazards as burning through the plastics material of the inspiratory inlet fitting <NUM> and/or otherwise generating toxic smokes/gases within the inspiratory inlet fitting <NUM> that may be inhaled by the patient. It has been discovered through testing that such a transition between heating and non-heating wires is unnecessary, and that portions of the support helixes <NUM> and <NUM> can be used as multi-conductor cables, as has been described.

<FIG> and <FIG>, taken together, depict various features of the plug <NUM> and the electrical connector <NUM> carried therein. As depicted, in some embodiments, the plug <NUM> may be formed from multiple separately fabricated plastic components, including the depicted face portion <NUM> and the depicted pair of "clamshell" portions <NUM>. In this depicted embodiment, much of the electrical connector <NUM> (with its electrical contacts <NUM> installed therein, and already soldered to the conductors <NUM> of the heating wires <NUM> of the support helix <NUM>) may be enclosed between the two clamshell portions <NUM>, which may be fastened to each other in any of a variety of ways. A portion of the support helix <NUM> adjacent the electrical connector <NUM> may also be enclosed between the two clamshell portions <NUM>. The face portion <NUM> may then be molded over the assembled pair of the clamshell portions <NUM> with the electrical connector <NUM> enclosed between the clamshell portions <NUM>. In so molding the face portion <NUM>, portions of the plastics material of the face portion <NUM>, while in a molten state, may fill various convolutions formed within each of the two clamshell portions <NUM> to further bond them together. In so doing, the face portion <NUM> may also seal spaces between the two clamshell portions <NUM> within which the electrical connector <NUM> is held, as well as the portion of the support helix that is also enclosed therebetween. In so doing, the electrical connections between the conductors <NUM> of the heating wires <NUM> and the electrical contacts <NUM> of the electrical connector <NUM> may be entirely enclosed to seal and protect those connections against moisture present in the respiratory gases conveyed through the inspiratory inlet fitting <NUM> to thereby prevent corrosion, etc..

Alternatively, in other embodiments, following the connection of the conductors <NUM> of the heating wires <NUM> of the support helix <NUM> to the electrical contacts <NUM> of the electrical connector <NUM>, the entire plug <NUM> may simply be molded around the electrical connector <NUM>. A portion of the support helix <NUM> adjacent the electrical connector <NUM> may also be enclosed within such a molded form of the plug <NUM>.

Regardless of the exact manner in which the plug <NUM> is formed and/or in which the electrical connector <NUM> is caused to be enclosed within the plug <NUM>, the portion of the plug <NUM> that extends furthest into the inspiration inlet fitting <NUM> may be shaped to cooperate with interior surface portions of the inspiration inlet fitting <NUM> to present a relatively unobstructed path for the flow of respiratory gases through the inspiration inlet fitting <NUM> with relatively smooth surfaces encountered by the respiratory gases throughout that path. More precisely, and as best seen in <FIG>, as well as in FIGURES ID, IE and 8A, the portion of the plug <NUM> that extends furthest into the inspiration inlet fitting <NUM> may be provided with a concave surface <NUM> that serves to define part of such a relatively unobstructed path with smooth surfaces for the flow of respiratory gases.

<FIG> and <FIG>, taken together, depict similar features of the plug <NUM> and the electrical connector <NUM> carried therein. As depicted, in some embodiments, the plug <NUM> may be formed from multiple separately fabricated plastic components, including the depicted face portion <NUM> and the depicted pair of clamshell portions <NUM>. In this depicted embodiment, much of the electrical connector <NUM> (with its electrical contacts <NUM> installed therein, and already soldered to the conductors <NUM> of the heating wires <NUM> of the support helix <NUM>) may be enclosed between the two clamshell portions <NUM>, which may be fastened to each other in any of a variety of ways. A portion of the support helix <NUM> adjacent the electrical connector <NUM> may also be enclosed between the two clamshell portions <NUM>. The face portion <NUM> may then be molded over the assembled pair of the claims clamshell portions <NUM> to form the plug <NUM> with the electrical connector <NUM> sealed in place therein in a manner similar to what has been previously described in reference to the plug <NUM>.

Alternatively, in other embodiments, following the connection of the conductors <NUM> of the heating wires <NUM> of the support helix <NUM> to the electrical contacts <NUM> of the electrical connector <NUM>, the entire plug <NUM> may simply be molded around the electrical connector <NUM>.

A portion of the support helix <NUM> adjacent the electrical connector <NUM> may also be enclosed within such a molded form of the plug <NUM>.

As with the plug <NUM>, regardless of the exact manner in which the plug <NUM> is formed and/or in which the electrical connector <NUM> is caused to be enclosed within the plug <NUM>, the portion of the plug <NUM> that extends furthest into the expiration outlet fitting <NUM> may be shaped to cooperate with interior surface portions of the expiration outlet fitting <NUM> to present a relatively unobstructed path for the flow of respiratory gases through the expiration outlet fitting <NUM> with relatively smooth surfaces encountered by the respiratory gases throughout that path. More precisely, and as best seen in <FIG>, as well as in FIGURES ID and IE, the portion of the plug <NUM> that extends furthest into the inspiration inlet fitting <NUM> may be provided with a concave surface <NUM> that serves to define part of such a relatively unobstructed path with smooth surfaces for the flow of respiratory gases.

It should be noted that, as depicted in <FIG> and <FIG>, as well as throughout others of the figures in this present application, the electrical connectors <NUM> and <NUM> may be provided with differing physical shapes as a keying mechanism to prevent incorrect electrical connections between the medical device <NUM> and each of the heating wires <NUM> and <NUM> within the hoses <NUM> and <NUM>, respectively. More specifically, the electrical connector <NUM> is depicted as being a so- called "monkey face" connector having a shape that includes three lobes in which two of the lobes are each occupied by one of the electrical contacts <NUM>. In contrast, the electrical connector <NUM> is depicted as having a more conventional elongate oval- like shape in which the electrical contacts <NUM> are positioned toward opposite ends of the of the oval-like shape. As will be familiar to those skilled in the art of such medical devices as ventilators and CPAP devices, this depicted
combination of forms of the electrical connectors <NUM> and <NUM> have become widely adopted for use in providing electric power for heating the hoses used with such medical devices.

As previously discussed, at the opposite end of the support helix <NUM> from the end that is connected to the electrical connector <NUM>, the conductors <NUM> of the pair of heating wires <NUM> may be electrically connected to each other through crimping, soldering, etc., to form an electrical loop with the pair of heating wires <NUM> through the support helix <NUM> for heating the interior of the inspiration hose <NUM>. Similarly, at the opposite end of the support helix <NUM> from the end that is connected to the electrical connector <NUM>, the conductors <NUM> of the pair of heating wires <NUM> may be similarly electrically connected to each other to form a separate electrical loop with the pair of heating wires <NUM> through the support helix <NUM> for separately heating the interior of the expiration hose <NUM>. As also previously discussed, the medical device <NUM> may operate each of these electrical loops separately and in different ways that may be selected to cause differing degrees of heating within each of the hoses <NUM> and <NUM>. Indeed, as also previously discussed, the heating wires <NUM> and <NUM> may be selected to have different resistances in recognition of such differences in the manner in which each may be used.

<FIG>, taken together, depict various aspects of forming an electrical "pigtail" <NUM> or <NUM> from a portion of the support helix <NUM> or <NUM> for use in connecting the heating wires <NUM> or <NUM> to the medical device <NUM> to be provided with electrical power therefrom. In a manner similar to the embodiments depicted and discussed in reference to.

<FIG>, <FIG> present embodiments of the use of a portion of the support helix <NUM> or <NUM> as an electrical cable to advantageously avoid the creation of a electrical terminations where a transition is made between the heating wires <NUM> or <NUM>, respectively, to non-heating wires. However, unlike the embodiments of <FIG> in which the connector <NUM> or <NUM> is carried within the plug <NUM> or <NUM> installed within the fitting <NUM> or <NUM>, respectively, in the embodiments of <FIG>, the connector <NUM> or <NUM> is located in the environment external to the fitting <NUM> or <NUM> at the end of an electrical pigtail <NUM> or <NUM>, respectively.

Each of <FIG> depicts a subset of the components of either the inspiratory hose assembly <NUM> or the expiratory hose assembly <NUM> toward the end thereof that is to be connected to the medical device <NUM>. More precisely, in each of <FIG>, depictions of one of the undermold couplings <NUM>, and of the wall <NUM> or <NUM> of the hose <NUM> or <NUM> has been omitted to enable the helical path of the support helix <NUM> or <NUM>, respectively, therein to be viewed more clearly. Additionally, in <FIG>, the depiction of either the inspiratory inlet fitting <NUM> or the expiratory outlet fitting <NUM> that is provided in <FIG> is also omitted to provide an uninterrupted view of the transition of the support helix <NUM> or <NUM> from its helical path for purposes of heating the interior of the hose <NUM> or <NUM> to a relatively straightened path for purposes of being used as an electrical cable to convey the heating wires <NUM> or <NUM> thereof to the connector <NUM> or <NUM>.

Turning more specifically to <FIG> and <FIG>, as depicted, where an end of a portion of the inspiratory hose <NUM> is inserted into a portion of the inspiratory inlet fitting <NUM>, or where an end of a portion of the expiratory hose <NUM> is inserted into a portion of the expiratory outlet fitting <NUM>, a portion of the support helix <NUM> or <NUM> is unwound from its helical path within the inspiratory hose <NUM> or <NUM> and is employed as an electrical cable to bring the heating wires <NUM> or <NUM> therein to the electrical connector <NUM> or <NUM> at an end of the electrical pigtail <NUM> or <NUM>, respectively.

More specifically, a portion of the support helix <NUM> or <NUM> is pulled out of the end of the hose <NUM> or <NUM> (i.e., unwound therefrom) where that end is inserted into the fitting <NUM> or <NUM>, respectively. The length of the unwound portion of the support helix <NUM> or <NUM> may be determined, at least in part, by the intended length of the electrical pigtail <NUM> or <NUM>. The unwound portion of the support helix <NUM> or <NUM> may then be straightened to at least some degree for use as an electrical cable. This unwinding of the portion of the support helix <NUM> may be performed prior to the threading of the depicted undermold coupling <NUM> (again, not shown for purposes of visual clarity) onto the end of the hose <NUM> or <NUM> that is to be inserted into the fitting <NUM> or <NUM>, respectively. As a result, the unwound portion of the support helix <NUM> extends beyond the end of the <NUM> or <NUM> onto which the undermold coupling <NUM> is threaded, thereby emerging from within the undermold coupling <NUM> and extending further into the interior of the <NUM> or <NUM> than the end of the hose <NUM> or <NUM>, respectively, onto which the undermold coupling <NUM> is threaded. The unwound portion of the support helix <NUM> or <NUM> may then be fed through a channel and/or opening defined by a portion of the fitting <NUM> or <NUM> to be caused to extend into the environment external to the fitting <NUM> or <NUM> to serve as the core of the electrical pigtail <NUM> or <NUM>.

Turning briefly to <FIG>, as depicted, the unwound portion of the support helix <NUM> or <NUM> may be covered in a sheath <NUM> or <NUM>, at least where the unwound portion of the support helix <NUM> or <NUM> emerges from the fitting <NUM> or <NUM>, respectively, and into the environment external thereto. Alternatively or additionally, the sheath <NUM> or <NUM> may cover at least part of the unwound portion of the support helix <NUM> or <NUM> within the fitting <NUM> or <NUM>. In some embodiments, the sheath <NUM> or <NUM> may be a length of heatshrink tubing that is sleeved over the unwound portion of the support helix <NUM> or <NUM> (at least the length thereof that is within the environment external to the fitting <NUM> or <NUM>), and then heated to cause the cross- section of the heatshrink tubing to shrink radially inward toward the exterior of the unwound portion of the support helix <NUM> or <NUM>. Such an application of heat may also be used to aid in the straightening of the unwound portion of the support helix <NUM> or <NUM> and/or to somewhat change the shape thereof to conform to the interior surface of the heatshrink tubing as the heatshrink tubing is caused to tightly surround the unwound portion of the support helix <NUM> or <NUM>, respectively (at least the length thereof that is within the environment external to the fitting <NUM> or <NUM>).

Turning again more specifically to <FIG> and <FIG>, the end of the unwound portion of the support helix <NUM> or <NUM> that extends toward the electrical connector <NUM> or <NUM> may be partly stripped away to remove at least enough of the flexible plastics material of the support helix <NUM> or <NUM> (and maybe also to strip away a portion of the sheath <NUM> or <NUM>) to expose enough of the heating wires <NUM> or <NUM> therein to enable forming an electrical connection with the contacts <NUM> or <NUM> of the electrical connector <NUM> or <NUM>, respectively. Again, this may also be done using typical wire stripping techniques. Also again, in separating the relatively short portion of the support helix <NUM> or <NUM> from the hose <NUM> or <NUM>, portions of the wall <NUM> or <NUM> (again, not shown for purposes of visual clarity) that extend between adjacent coils of the support helix <NUM> or <NUM> that are included in the unwound portion thereof may be trimmed away.

It has been discovered through testing that a transition from the heating wires <NUM> or <NUM> of the support helix <NUM> or <NUM>, and to non-heating wires to form the electrical pigtail <NUM> or <NUM> is unnecessary, especially where the electrical pigtail <NUM> or <NUM> additionally includes the sheath <NUM> or <NUM> to provide additional insulation against the heat that may be generated within the electrical pigtail <NUM> or <NUM> by the heating wires <NUM> or <NUM>, respectively, therein.

Claim 1:
A method of forming a hose (<NUM> or <NUM>) comprising:
extruding a continuous web of plastics material from a first extruder (107a) of a hose making apparatus (<NUM>);
helically winding the extruded web about a mandrel or at least one rotating rod (<NUM>) of the hose making apparatus (<NUM>) to form a wall (<NUM> or <NUM>) of the hose (<NUM> or <NUM>) about a central axis (<NUM>) of the hose (<NUM> or <NUM>);
feeding a first electrical wire (<NUM> or <NUM>) into a second extruder (107b);
extruding a first continuous bead (<NUM> or <NUM>) of plastics material around the first electrical wire (<NUM> or <NUM>) from the second extruder (107b), wherein:
the first electrical wire (<NUM> or <NUM>) is positioned at a first location within a cross-section of the first extruded bead (<NUM> or <NUM>); and
the cross-section of the first extruded bead (<NUM> or <NUM>) defines an exterior of the first extruded bead that comprises a first bonding surface (<NUM> or <NUM>) covering a portion of the exterior;
cooling the first extruded bead (<NUM> or <NUM>) sufficiently to cool the plastics material adjacent the first location within the cross-section of the first extruded bead (<NUM> or <NUM>) to prevent migration of the first electrical wire (<NUM> or <NUM>) away from the first location;
re-heating the first bonding surface (<NUM> or <NUM>) of the first extruded bead (<NUM> or <NUM>) sufficiently to cause the plastics material of the first bonding surface (<NUM> or <NUM>) to become molten; and
helically winding the first extruded bead (<NUM> or <NUM>) onto and about an external surface of the wall (<NUM> or <NUM>) of the hose (<NUM> or <NUM>) formed from the helical winding of the extruded web such that the first bonding surface (<NUM> or <NUM>) is put into contact with, and then becomes bonded to, the wall (<NUM> or <NUM>) of the hose (<NUM> or <NUM>) to become a first support helix (<NUM> or <NUM>) that incorporates the first electrical wire (<NUM> or <NUM>).