Abstract:
Apparatus for connecting a patient to a breathing device such as a respirator, anesthesia machine or the like is disclosed, including a Y-piece including a patient attachment tube, and a pair of additional attachment tubes adapted for connection to an inhalation tube and an exhalation tube, respectively, and including a bacteria filter disposed within the apparatus and separating the patient attachment tube from the two additional attachment tubes so that gases passing between the patient attachment tube and these two attachment tubes along a predetermined flow path must pass through the bacteria filter. In one embodiment the apparatus includes a partition wall arranged for separating inhaled air and exhaled air during passage through the Y-piece.

Description:
This is a continuation of application Ser. No. 07/698,717 filed May 10, 1991, now abandoned. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to apparatus for connecting patients to breathing devices. More particularly, the present invention relates to apparatus for connecting patients to respirators, anesthesia machines and the like. 
     Still more particularly, the present invention relates to such apparatus including a Y-piece which includes an attachment nipple directed to the patient and two attachment nipples for attachment to an inhalation tube and an exhalation tube, respectively. 
     BACKGROUND OF THE INVENTION 
     As used in connection with the present application, the expression &#34;Y-piece&#34; also includes shapes other than that of conventional &#34;Y.&#34; Of significance is only the fact that the patient attachment piece can be connected to an inhalation and exhalation tube, respectively. The expression &#34;Y-piece&#34; thus also includes, for example, T-connectors and connectors for coaxially connecting arranged inhalation and exhalation tubes. 
     In addition, the term &#34;patient attachment piece&#34; is also used in connection with this application. The &#34;patient attachment piece&#34; is intended to be attached to the portion of the Y-piece which is directed towards the patient. These patient attachment pieces can, for example, be designed in accordance with U.S. Pat. No. 4,516,573. In this patent there is thus described a bellowed patient attachment piece, which contains a wad of moisture- and heat-absorbing material. In this manner, heat and moisture are taken up from the exhaled gas and provided to the inhaled gas. Such patient attachment pieces are often connected with various types of Y-pieces and may be equipped with various types of bacterial filters. The more components which are connected, however, lead to a bulkier construction, which can thus become rather inconvenient for the patient. Furthermore, the connection of a number of different components creates the risk of both leakage and, on the other hand, improperly connected components. 
     When a patient is attached to a respirator, anesthesia machine or the like, there also arises a need for continuous or intermittent sampling of the exhaled gas and for proximal pressure measuring. This should take place as close to the patient as possible, and can occur, for example, in the manner described in U.S. Pat. No. 4,838,258; i.e., by means of a tube which extends from the respirator itself, through the exhalation tube, to a point near the patient. The disadvantage with this construction, however, is that the withdrawn sample can be, on the one hand, extremely moist, and, on the other hand, contaminated with bacteria. 
     Furthermore, in the case of conventional Y-pieces, a certain dead volume must be taken into account. By dead volume is meant the quantity of exhaled gases which return to the patient. This dead volume rapidly increases if the Y-piece is provided with extra functions, such as with a bacteria filter, as described, for example, in Swedish Patent Application No. 90.02162/7, filed Jun. 18, 1990. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, apparatus has now been discovered for connecting a patient to breathing devices, such as respirators and anesthesia machines, comprising a patient attachment tube member extending in a first direction and having a first end and a second end, first and second attachment tube members extending in a second direction, said first and second attachment tube members being adapted for connection to an inhalation tube and an exhalation tube, respectively, and each including a first end and a second end, said second direction being different from said first direction such that said first end of said patient attachment tube member is proximate to said first ends of said first and second attachment tube members and said second end of said patient attachment tube member is distal from said second ends of said first and second attachment tube members, connecting means connecting said first end of said patient attachment tube member to said first ends of said first and second attachment tube members, and a bacteria filter disposed within said apparatus and separating said first end of said patient attachment tube member from said first ends of said first and second attachment tube members, whereby gases passing between said patient attachment tube member and said first and second attachment tube members along a predetermined flow path must pass through said bacteria filter. 
     In accordance with one embodiment of the apparatus of the present invention, the apparatus includes a patient attachment element attached to the patent attachment tube member for use by the patient, and the apparatus has a flow-through area which is greater than the flow-through area of the patient attachment element. 
     In accordance with another embodiment of the apparatus of the present invention, the patient attachment tube member comprises a first part of the apparatus, and the first and second attachment tube members comprise a second part of the apparatus, the first and second parts being attached to each other to form the connecting means with the bacteria filter therebetween. 
     The present invention relies in considerable part in the bacteria filter being arranged within the apparatus or Y-piece itself. In order to reduce breathing resistance therein, the flow-through area of the Y-piece can thus be enlarged in comparison to that of the patient attachment piece. By reducing the number of parts included in the connection arrangement itself, choking can be reduced, since this can easily occur with the apparatus used in the past in which a number of components are connected together. 
     In accordance with one construction of the present invention, which is relatively simple, particularly in terms of the ability to manufacture same, the Y-piece is formed from two bowl-shaped parts, and the bacteria filter is clamped between these parts substantially perpendicular to the flow-through direction or the above-mentioned predetermined flow path. 
     In accordance with this aspect of the present invention, the Y-piece normally includes three attachment nipples; namely, one for patient attachment piece, one for the inhalation tube, and one for the exhalation tube. From the point of view of manufacturing, a particularly suitable construction is obtained when these nipples are arranged substantially parallel to each other. Thus, in accordance with this embodiment of the present invention, the patient attachment tube member and the first and second attachment tube members comprise such nipples extending substantially parallel to each other. 
     In accordance with another embodiment of the apparatus of the present invention, the apparatus has a substantially circular configuration, so as to maximize the flow-through area of the apparatus in proportion to its volume, while at the same time the length of the apparatus and the direction of the flow is restricted to that which its function permits. 
     In accordance with a preferred embodiment of the apparatus of the present invention, the apparatus includes sample withdrawal means for obtaining a gas sample from the apparatus during exhalation therethrough. This gas sample is thus provided in the flow direction for exhalation downstream of the bacteria filter. In this manner, considerably dryer gas samples can be obtained without secretions from the patient. The proximal pressure of the patient can also be measured through this outlet. 
     In a preferred embodiment the sample withdrawal means is located on the opposite side of the bacteria filter as compared to the patient attachment tube member. 
     In accordance with a preferred embodiment of the apparatus of the present invention, a patient attachment element is attached to the patient attachment tube member, preferably comprising a flexible tubular member which more preferably contains a heat and moisture exchange medium which is preferably in the form of a wad or the like of flexible material such as fibers, and which has the ability to take up heat and moisture from exhaled gas and subsequently deliver this heat and moisture to the inhaled gas. The manner in which this is achieved is described in more detail in U.S. Pat. No. 4,516,573, the disclosure of which is incorporated herein by reference thereto. 
     In accordance with a preferred embodiment of the apparatus of the present invention, the sample withdrawal means is preferably arranged in the form of a nipple which is substantially in the middle of the Y-piece which, in a direction perpendicular to the flow-through direction, has a somewhat drawn-out flow-through area, such as being substantially oval or having a rounded rectangular-shaped configuration, and is preferably located between the attachment nipples for the inhalation and exhalation tubes, and is preferably parallel thereto. 
     In an alternate embodiment, however, the sample withdrawal outlet can have the form of a nipple which is angled with respect to the other nipples. In both cases, however, it is important that the sample withdrawal outlet be shieldably arranged between the attachment nipples for the inhalation and exhalation tubes, respectively. 
     In accordance with a preferred embodiment of the apparatus of the present invention, the sample withdrawal means includes first tube means extending into contact with the bacteria filter. Preferably, the sample withdrawal means includes second tube means located on the same side of the bacteria filter as the patient attachment tube member, and the second tube means also extends into contact with the bacteria filter. 
     In a preferred embodiment, the second tube means extends into the patient attachment tube member, and preferably the first and second tube means are located on opposite sides of the bacteria filter, and are both in pressure contact therewith. Preferably, the first and second tube means each include widened portions at the ends of the first and second tube means which are in contact with the bacteria filter, and preferably these widened portions comprise cone-shaped or cylindrical configurations. 
     The Y-pieces of the present invention require a certain minimum volume. By way of example, the attachment nipples should have a certain standard dimension. In order for this volume to affect the withdrawal sample as little as possible, the sample withdrawal outlet is thus suitably connected to a first sample withdrawal tube which extends from the outlet to the bacteria filter, and which can, via the bacteria filter, be connected to a second sample withdrawal tube which extends from the filter towards the patient attachment piece, and which preferably extends up to and possibly into this patient attachment piece. In this manner, the effect of the inner volume of the Y-piece on the sample withdrawal tube is substantially eliminated. 
     As indicated above, the sample withdrawal means preferably is further simplified when the first and second withdrawal tubes are arranged on either side of the bacteria filter and are in pressured contact therewith by means of widened portions, such as cone-shaped and/or cylindrical funnel-like portions which are at right angles to the direction of flow. In this manner, the simplification of flow of the sample through the bacteria filter is achieved while leakage between the inner sample withdrawal tube and the atmosphere surrounding it is substantially prevented. 
     In accordance with another embodiment of the apparatus of the present invention, the first and second parts thereof include bowl-shaped inner surfaces in contact with the bacteria filter, and at least the second part, which comprises the first and second attachment tube members, includes web means for supporting the sample withdrawal means therein. 
     In accordance with another embodiment of the apparatus of the present invention, patient attachment element also serves as a heat and moisture exchanger by being equipped with a wad or the like of the above-mentioned type. In a preferred embodiment, the wad of flexible material is impregnated with an anti-bacterial agent, such as clorhexidine or hydrogen peroxide, and or with a hygroscopic substance, such as magnesium chloride, lithium chloride and calcium chloride. 
     In accordance with a preferred embodiment of the apparatus of the present invention, the wad of flexible material comprises fibers of plastic material having a first melting point, and they are coated with a plastic material having a second melting point, the second melting point being lower than the first melting point, whereby the fibers are bonded by heating the fibers to the second melting point. 
     Preferably, the fibers of plastic material having a first melting point comprise polypropylene and the plastic material having a second melting point comprises polyethylene. In this manner, the breaking off of material from the fiber wad and its transmittal into the patient&#39;s respiratory organs is effectively prevented. 
     In accordance with another embodiment of the apparatus of the present invention, the patient attachment element includes at least a portion comprising transparent material, which portion is free of any added material within the interior thereof, so as to serve as a secretion trap or inspection zone therefor. This portion of the patient attachment element is preferably located nearest the patient. 
     In certain embodiments, however, such as in connection with anesthesia treatments, the patient attachment piece is not required. This is therefore suitably arranged to be disconnectable from the Y-piece or patient attachment tube member thereof. 
     In accordance with another embodiment of the apparatus of the present invention, both the first and second parts include web means for supporting the sample withdrawal means. 
     In accordance with another embodiment of the apparatus of the present invention, the apparatus includes partition means extending from a point between the first and second attachment tube members towards the patient attachment tube member, so as to separate inhaled air and exhaled air during their respective passage through the apparatus in the predetermined flow direction. 
     Preferably, the partition means extends at least up to the bacteria filter. More preferably, in the embodiment where the patient attachment tube member comprises a first part of the apparatus and the first and second attachment tube members comprise a second part of the apparatus, both the first and second parts include partition means, whereby the partition means is located on either side of the bacteria filter so as to clamp and support the bacteria filter therebetween. Preferably, the partition means on both the first and second parts includes a first partition means portion and a second partition means portion. In this manner, both of the preferably bowl-shaped portions of the Y-piece are provided with internal stiffening webs which are arranged so as not to disturb the flow-through as much as possible, such as by being radially directed in relation to the principal flow-through direction, while also being arranged to support the bacteria filter on both sides thereof. 
     In accordance with another embodiment of the apparatus of the present invention, the patient attachment tube member includes a collar member concentrically located therewithin for facilitating connection to various attachment parts, either exteriorly or interiorly of the patient attachment tube member, the partition means extending only between the collar member and the patient attachment tube member. 
     In accordance with the present invention, apparatus is also provided for connecting a patient to breathing devices comprising a patient attachment element, a Y-piece for connecting the patient attachment element to an inhalation tube and an exhalation tube, the Y-piece including a bacteria filter therein, and a sample withdrawal member located downstream of the bacteria filter with respect to the patient attachment element, the sample withdrawal member including a sample withdrawal tube extending towards the bacteria filter for contact therewith, so that bacteria-free samples can be obtained from the sample withdrawal means through the bacteria filter. 
     In order that samples can thus be taken from a location as close to the patient as possible, the first sample withdrawal tube can be connected, through the bacteria filter, to a second sample withdrawal tube which extends from the bacteria filter towards the patient attachment piece, and preferably up to and possibly into the patient attachment piece. The filtering of the withdrawn samples is thereby simplified if the first and second sample withdrawal tubes are arranged on either side of the bacteria filter and are in pressurized contact therewith by means of widened portions, such as the cone-shaped and/or cylindrical funnel-like portions, and preferably at right angles to the flow direction discussed hereinabove. 
     The moisture content of the withdrawn samples therefrom is reduced if the patient attachment piece thus contains a heat and moisture exchange system in the form of a wad or the like of a flexible material such as fibers, which has the ability to withdraw heat and moisture from exhaled gases and subsequently deliver same to the inhaled gases. Preferably, the complete patient attachment piece is made from a flexible material. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The following detailed description of the present invention can be more readily appreciated with reference to the drawings, in which: 
     FIG. 1 is a side, elevational, sectional view of a Y-piece comprising an embodiment of the apparatus of the present invention; 
     FIG. 2 is a top, elevational view of the apparatus shown in FIG. 1; 
     FIG. 3 is a side, elevational, partially sectional view of another embodiment of the apparatus of the present invention; 
     FIG. 4 is a bottom, elevational view of the apparatus shown in FIG. 3; 
     FIG. 5 is a bottom, elevational, partially sectional view of another apparatus in accordance with the present invention; 
     FIG. 6 is a front, partially plan view of the apparatus shown in FIG. 5; 
     FIG. 7 is a side, elevational, partially plan view of the apparatus shown in FIG. 5; 
     FIG. 8 is an elevational, cross-sectional view of the apparatus shown in FIG. 5 taken along line VIII--VIII thereof, with the filter removed; 
     FIG. 9 is a bottom, elevational, partially sectional view of another apparatus in accordance with the present invention; 
     FIG. 10 is a front, elevational, partially plan view of the apparatus shown in FIG. 9; 
     FIG. 11 is a side, elevational, partially plan view of the apparatus shown in FIG. 9; 
     FIG. 12 is an elevational, cross-sectional view of the apparatus shown in FIG. 9 with the filter removed therefrom; 
     FIG. 13 is a side, elevational, sectional view of another apparatus in accordance with the present invention; 
     FIG. 14 is a bottom, elevational view of the apparatus shown in FIG. 13; 
     FIG. 15 is a top, elevational view of the apparatus shown in FIG. 13; 
     FIG. 16 is a side, elevational, sectional view of another apparatus in accordance with the present invention; 
     FIG. 16a is a partial, side, sectional, enlarged view of a portion of the apparatus shown in FIG. 16; 
     FIG. 17 is a bottom, elevational view of the apparatus shown in FIG. 16; and 
     FIG. 18 is a top, elevational view of the apparatus shown in FIG. 16. 
    
    
     DETAILED DESCRIPTION 
     Turning to the Figures, in which like numerals refer to like portions thereof, FIGS. 1 and 2 show sectional and end views, respectively, of a Y-piece which is intended to be included in the connection arrangement according to the present invention. 
     The Y-piece shown in FIGS. 1 and 2 comprises two bowl-shaped parts, 1 and 2, with a bacteria filter 3 clamped therebetween. The upper bowl-shaped part 1 is provided with a nipple 4 which is intended to be connected to a patient attachment piece. The lower bowl-shaped part 2 is provided with two parallel nipples, 5 and 6, which are intended to be connected to an inhalation tube and an exhalation tube, respectively, which are, in turn, intended to be connected to a respirator, anesthesia machine or the like. 
     The bacteria filter 3 is clamped between a circular ridge 7 on the upper bowl-shaped part 1, and a circular groove 8 in the lower bowl-shaped part 2. This groove 8 is formed from an outer flange 9 and an inner ridge 10. The flange 9 is terminated at its outer portion by a radially extending partial flange 11, which is intended to be fixed to the upper bowl-shaped part 1 by, for example, glueing or welding, and preferably by ultrasonic welding. The concentricity of the two bowl-shaped parts, 1 and 2, is facilitated by an outer peripheral flange 12 on the upper bowl-shaped part 1. 
     The lower bowl-shaped part 2 further comprises a sample withdrawal outlet in the form of a nipple 14, which is preferably provided with an inner or outer screw thread 15, or other such fixing means. The nipple 14 is connected to a first sample withdrawal tube 16 which, in turn, via filter 3, is connected to a second sample withdrawal tube 17. Both of these sample withdrawal tubes, as well as the filter 3, are supported by radially extending support webs 18 and 19, respectively. The sample withdrawal tube 17 terminates on its inner end with a widened cylindrical portion 20, which, via the filter 3, presses against a corresponding portion of the sample withdrawal tube 16. As is evident from FIG. 2, the sample withdrawal tube 17 is located between four radially directed support webs 19. 
     Turning to FIGS. 3 and 4, there is shown a modified embodiment of a Y-piece in the connection arrangement according to the present invention. This construction corresponds in principle with that according to FIGS. 1 and 2. Thus, the same reference numerals have been used, but with the addition of a prime mark. The most significant difference is that the attachment nipples 5&#39; and 6&#39;, respectively, are angularly formed. Furthermore, the sample withdrawal tubes 16&#39; and 17&#39; in this case have been given a somewhat different shape. 
     In FIGS. 5 through 8, there is shown a somewhat more complete construction of an embodiment of the connection arrangement according to the present invention. Once again, this embodiment generally corresponds with the embodiment discussed above. Thus, the same reference numerals are employed with respect to corresponding details therein, but with the addition of a double prime mark. Reference numerals 5&#34; and 6&#34; thus denote two nipples which are intended to be attached to an inhalation tube and an exhalation tube, respectively. The bacteria filter itself is denoted by reference numeral 3&#34;. Reference numeral 14&#34; denotes a sample withdrawal nipple which is connected to a first sample withdrawal tube 16&#34;. This sample withdrawal tube 16&#34; is, in turn, via filter 3&#34;, in contact with a second sample withdrawal tube 17&#34;. Reference numeral 4&#34; denotes a nipple by means of which the Y-piece is connected to a patient attachment piece 21&#34;. This patient attachment piece 21&#34; is preferably designed substantially in accordance with the description in U.S. Pat. No. 4,516,573. It is, however, preferably of uniform thickness. Within the patient attachment piece there is preferably a wad 22&#34; or the like of a moisture- and heat-absorbing material which serves to take up heat and moisture from the exhaled gas and pass same to the inhaled gas. Finally, in FIG. 5, reference numeral 23&#34; denotes an attachment pipe or cone by means of which the patient attachment piece 21&#34; can be connected to a tracheal tube or the like. 
     The Y-piece shown in FIGS. 5 through 8 also consists of two bowl-shaped parts 1&#34; and 2&#34;, respectively, but differs from the above-described Y-pieces in that, for example, these parts have been given a rectangular shape with rounded edges or corners. Furthermore, the attachment nipples 5&#39; and 6&#39; are arranged at a different angle as compared, for example, to that shown in FIGS. 3 and 4. Finally, reference numeral 25&#39; denotes a dome which is directed towards the interior of the Y-piece and within which the sample withdrawal nipple 14&#39; is arranged. In light of this arrangement, the Y-piece&#39;s inner volume is reduced, while the sample withdrawal tube 16&#39; is stabilized. 
     The construction according to FIGS. 9 through 12 substantially corresponds to that according to FIGS. 5 through 8, and corresponding details thereof have thus been given the same reference numerals, but with the suffix a instead of the double prime marks used in FIGS. 5 through 8. The construction according to FIGS. 9 through 12 differs from that according to FIGS. 5 through 8 in that the nipples 5a and 6a are arranged parallel to the nipple 4a. Furthermore, the fiber wad 22a does not fill the entire patient attachment piece 21a. In this case, a free space 24a is left nearest to the patient, and is intended to serve as a secretion trap, and can also serve as an inspection zone if the patient attachment piece is made from a transparent material. Finally, reference numeral 25a denotes a dome which is directed towards the interior of the Y-piece, and within which the sample withdrawal nipple 14a is arranged. In light of this arrangement, the Y-piece&#39;s inner volume is reduced, while the sample withdrawal tube 16a is stabilized. 
     Turning next to FIGS. 13 through 15, a preferred embodiment of the connection arrangement according to the present invention is shown. Even though this apparatus does not have the shape of a conventional &#34;Y,&#34; in practice it is still referred to as a &#34;Y-piece.&#34; This Y-piece comprises an attachment nipple 1b which is directed towards the patient, and two attachment nipples, 2b and 3b, for connection to an inhalation tube and an exhalation tube, respectively. This construction is also characterized by a partition wall 4b which is arranged to separate inhaled air from exhaled air during their passage through the Y-piece from the inlets for both the attachment nipples, 2b and 3b, to and from the patient attachment nipple 1b. 
     The construction shown in FIGS. 13 through 15 consists of two parts or halves, 5b and 6b, in which the first part 5b comprises the patient attachment nipple 1b, and the second part 6b comprises the two other nipples, 2b and 3b. A filter 7b is clamped between these two parts. The filter has a porosity such that it does not seriously restrict the flow-through of inhaled air, but nevertheless stops bacteria. 
     The partition wall 4b should extend at least up to the filter 7b. Preferably, however, it continues with an extension portion 4&#39;b into the part 5b, and preferably up to the inner edge 8b of an inwardly directed collar 9b in the patient attachment nipple 1b. This collar 9b facilitates connection of this apparatus to attachment parts having various different size, either interiorly or exteriorly. If the partition wall 4&#39;b extends into the collar 9b, then internal attachment is hindered. However, it is still possible to effect external attachment at the same time that the dead volume of the Y-piece can be said to be zero, or substantially zero. If the part 5b is provided with a partition wall 4&#39;b, then under all circumstances this should extend through the space between the collar 9b and the nipple 1b. 
     In FIG. 15, it is noted that the part 5b can be provided with a further partition wall 10b. This does not separate the inhaled and exhaled air, but is instead intended to merely support the filter 7b. The part 6b can also be provided with such a supporting partition wall. this is, however, not shown in this embodiment. 
     A Y-piece substantially corresponding to FIGS. 13-15 with the partition walls 4b and 4&#39;b, was compared to a conventional Y-piece. Thereafter, a corresponding Y-piece without partition walls was compared with similar conventional Y-pieces. The comparison showed that the embodiment with partition walls had substantially the same dead volume as a conventional Y-piece. Corresponding Y-pieces without partition walls, however, had an increased dead volume in relation to the conventional Y-piece. 
     FIGS. 16 through 18 show another embodiment of the present invention. This embodiment corresponds in principle with that according to FIGS. 13 through 15, and the same reference numerals have thus been used, but with the suffix c in this case. The two joined parts or halves are thus denoted by 5c and 6c, respectively. The part 5c includes the patient attachment nipple 1c, and the part 6c includes the two other nipples, 2c and 3c. The partition wall, which is a significant element of the present invention, is denoted by reference numeral 4c, and the supporting partition wall by reference numeral 10c. A filter 7c is clamped between the two parts, 5c and 6c. This embodiment differs from that according to FIGS. 13 through 15 in that it is provided with a sample withdrawal outlet 11c arranged between the two nipples, 2c and 3c. This sample withdrawal outlet 11c is extended by a sample withdrawal tube 12c, which extends up to the filter 7 c. On the other side of the filter, a second sample withdrawal tube 13c continues and extends up to the outer orifice of the patient attachment nipple 1c. Both the sample withdrawal tubes 12c and 13c are formed in one piece with the partition wall 4c. In this manner, and by use of a suitable design, the two parts 5c and 6c are given a suitable shape for injection molding. They can thus be injection molded with the air of relatively simple equipment. 
     Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.