Y-piece connector for ventilator

Abstract: Connection arrangement for connecting a patient to a respirator, anaesthesia machine or similar, comprising a patient attachment piece, a so-called Y-piece (1,2) arranged to join the patient attachment piece to an inhalation tube and an exhalation tube, respectively, and a bacteria filter (3). The connection arrangement according to the invention is characterized in that a sample withdrawal outlet (14), arranged in the exhalation flow direction after the bacteria filter, is connected to a sample withdrawal tube (16), which extends from the bacteria filter (3) to the outlet (14) and is arranged so as to take bacteria-free samples through said filter (3).

Description: TECHNICAL FIELD The present invention relates to a connection arrangement for connecting a patient to a respirator, anaesthesia machine or similar, of the type mentioned in the preamble of claim 12 and a Y-piece for the type mentioned in the preamble of claim 1 for use in such a connection arrangement. From the following description it will be evident that the expression "Y-piece" also includes shapes other than a conventional "Y". Of importance is only that said patient attachment piece is able to be connected to an inhalation resp an exhalation tube. The expression "Y-piece" also includes for example T-connections and even connections for connecting coaxially arranged inhalation and exhalation tubes. BACKGROUND A Y-piece with a sample withdrawal outlet extending perpendicular to the flow of the air in the Y-piece is known from US-A 4 558 708 which is used as a basis for the preambles of claims 1 and 12, respectively. The patient attachment piece can by way of example be designed in accordance with US-A-4 516 573. In this patent there is described a bellowed patient attachment piece which contains a wad of moisture and heat absorbing material. In this way heat and moisture is taken up from the exhaled gas and given to the inhaled gas. Such patient attachment pieces are often connected with various types of Y-pieces and are possibly also equipped with various types of bacteria filters. The more components which are connected leads to a bulkier construction which can be inconvenient for the patient. Furthermore, the connection of a plurality of components leads to the risk of, on the one hand, leakage and, on the other hand, incorrectly connected components. Another problem is that the so called dead volume for the breathing gas increases when a plurality of components are combined. The same is also often true for samples taken at a distance from the patient. WO-A-8904864 describes a sample withdrawal tube which samples exhaled air after it has passed through a bacteria filter in a regenerative heat and moisture exchanger. However, the withdrawal tube samples air which can contain unfiltered inhalation air from the dead volume of the exchanger as well as filtered exhalation air from the patient. With the attachment of a patient to a respirator, anaesthesia machine or similar, the need arises for a continuous or intermittent sampling of the exhaled gas respectively a proximal pressure measuring. This should take place as close to the patient as possible and can occur for example in the way described in US-A-4 838 258, i.e. with the help of a tube which extends from the respirator itself through the exhalation tube to a point near the patient. The disadvantage with the construction described in this patent is, however, that the withdrawn sample can be, on the one hand, very moist, and, on the other hand, contaminated with bacteria. DESCRIPTION OF THE INVENTION The above mentioned problems are reduced or eliminated according to the present invention which relates to a Y-piece, for use in a connection arrangement for connecting a patient to a respirator, anaesthesia machine or similar, wherein said Y-piece comprises a sample withdrawal outlet wherein a bacteria filter is mounted in said Y-piece substantially perpendicular to the through-flow direction, and the sample withdrawal outlet is arranged in the exhalation flow direction after the bacteria filter and is connected to a sample withdrawal tube which extends from the bacteria filter to the outlet and is arranged so as to take bacteria-free samples through said filter. The present invention also relates to connection arrangement for connecting a patient to a respirator, anaesthesia machine or similar, comprising a patient attachment piece, a Y-piece, arranged to join the patient attachment piece to an inhalation resp exhalation tube, wherein the Y-piece is a Y-piece of the type described above. In this way considerably dryer gas samples are obtained without secretion from the patient. The proximal pressure of the patient can also be measured via this outlet. In order to reduce the dead volume the bacteria filter is arranged within the Y-piece itself. In order that samples can be taken from as close to the patient as possible, the first sample withdrawal tube can via the bacteria filter be connected to a second sample withdrawal tube which extends from the filter towards the patient attachment piece and preferably up to and, possibly into this piece. The filtering of the withdrawn samples is hereby simplified, if the said first and second sample withdrawal tubes are arranged on either side of the bacteria filter and are in pressurized contact therewith via a at right angles to the flow direction widened portion, for example a cone-shaped and/or cylindrical funnel-like portion. The moisture content of the withdrawn sample is reduced, if the patient attachment piece contains a heat and moisture exchange system in the form of a wad or similar of a flexible material, such as fibres, with the ability to take heat and moisture from exhaled gas and subsequently deliver this to the inhaled gas. Preferably the complete patient attachment piece is made from a flexible material. Such a heat and moisture exchange system is disclosed in US-A-4 516 573. In order to reduce the breathing resistance, the through-flow area of the Y-piece can hereby be enlarged in comparison with that of the patient attachment piece. By reducing the number of parts included in the connection arrangement, choking is also reduced, since otherwise this easily occurs with the connection of the various components. A simple construction with a view to manufacturing is achieved if the Y-piece is formed from two bowl-shaped parts and the bacteria filter is clamped between these parts substanially perpendicular to the through-flow direction. The Y-piece of the connection arrangement normally includes three attachment nipples, namely one for the patient attachment piece, one for the inhalation tube and one for the exhalation tube. From a manufacturing point of view a particularly suitable construction is obtained when these nipples are arranged substanially parallel to each other. Preferably the Y-piece's through-flow area is maximized in proportion to its volume through a substanially circular form, whilst its length in the flow direction is restricted to that which the function allows. The sample withdrawal outlet is suitably arranged in the form of a nipple substanially in the middle of a Y-piece with, in a direction perpendicular to the through-flow direction, a somewhat drawn out through-flow area, for example substanially oval or rounded-rectangular shaped, between the attachment nipples for the inhalation resp exhalation tubes and preferably parallel to these nipples. Alternatively the sample withdrawal outlet can have the form of a nipple which is angled in respect to the other nipples. Important in both cases is, however, that it is shieldably arranged between the attachment nipples for the inhalation resp exhalation tubes. The Y-piece requires a certain minimum volume. By way of example the included attachment nipples should have a certain standard dimension. In order that this volume affects the withdrawal sample as little as possible, the sample withdrawal outlet is connected to the first sample withdrawal tube which extends from the outlet to the bacteria filter. This sample withdrawal tube can, as mentioned above, via the bacteria filter, be connected to a second sample withdrawal tube which extends from the filter towards the patient attachment piece and preferably up to and, possibly, into this piece. In this way the effect of the Y-piece's inner volume on the withdrawal sample is substantially eliminated. The sample withdrawal is further simplified when said first and second sample withdrawal tubes are arranged on either side of the bacteria filter and are in pressured contact therewith via an at right angles to the flow direction widened portion, for example a cone-shaped and/or cylindrical funnel-like portion. In this way the simplification of, amongst other things, the flow of the sample through the bacteria filter is achieved, whilst leakage is prevented between the inner sample withdrawal tube and the atmosphere surrounding it. To secure the position of, and the contact between, said sample withdrawal tubes, one or both bowl-shaped halves of the Y-piece can be provided with support webs for one or both tubes. Should the connection arrangement serve at the same time as a heat and moisture exchanger by being equipped with a wad, or similar, of the above-mentioned type, then this should suitably be impregnated with an antibacterial agent, for example chlorhexidine or hydrogen peroxide, and/or with a hygroscopic substance, such as magnesium chloride, lithium chloride or calcium chloride. In a preferred embodiment of the connection arrangement according to the invention, the above-mentioned wad or similar consists of fibres of a plastic material having a certain melting point, such as polypropylene, which are coated with another plastic material having a lower melting point, such as polyethylene, with the aid of which the fibres are bounded by heating to said lower melting point. In this way the breaking off of material from the fibre wad and its transmittal in to the patient's respiratory organs is effectively prevented. Preferably at least one part of the patient attachment piece is made from transparent material. This part, which preferably is located nearest the patient, is left free from other material in order to serve as a secretion trap and/or inspection zone. In certain circumstances, for example in connection with anaesthesia treatment, the patient attachment piece is not required. This is therefore suitably arranged to be disconnectable from the Y-piece. Said sample withdrawal outlet is appropriately arranged in a dome, or similar, directed towards the interior of the Y-piece and which is arranged to stabilize the outlet whilst also reducing the inner volume of the Y-piece. Preferably both bowl-shaped parts of the Y-piece are provided with internal stiffening webs which are so arranged that they disturb the through-flow as little as possible, for example by being radially directed in relation to the principal through-flow direction, whilst also being arranged to support the bacteria filter on both sides. Due to the fact that the present invention, according to the applicant, is closely related to the invention according to co-pending European patent application 91.108316.0 (EP 462 412) (parent application to the present divisional application) both related to the same product, the product in its entirety is described in the following, inclusive modifications. In such a way both inventions can be easier understood. DESCRIPTION OF THE DRAWINGS Figure 1 shows a section through a Y-piece according to the invention. Figure 2 shows the same Y-piece as in Figure 1, but from above. Figure 3 shows a somewhat modified Y-piece. Figure 4 shows the last-mentioned Y-piece seen from underneath. Figure 5 shows schematically a somewhat more complete connection arrangement according to the invention. Figure 6 shows a plan view of the connection arrangement according to Figure 5. Figure 7 shows a section through a nipple and a side view of another nipple belonging to the Y-piece which is included in the connection arrangement according to Figure 5. Figure 8 shows a section along line VIII-VIII in Figure 5, but without the filter. Figures 9-12 show views corresponding to Figures 5-8 of a modified embodiment of the connection arrangement according to the invention. Figure 13 shows a further embodiment of a Y-piece. At the same time fig 13a shows, on a larger scale, a part of fig 13. Figure 14 shows the Y-piece according to Figure 13 seen from beneath and Figure 15 shows the same seen from above. BEST MODE OF CARRYING OUT THE INVENTION Figures 1 and 2 show a section resp end view of a Y-piece according to the invention which is intended to be included in a connection arrangement also according to the invention. This Y-piece 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 resp an exhalation tube, which in turn are intended to be connected to a respirator, anaesthesia machine or similar. The bacteria filter 3 is clamped between a circular ridge 7 on the upper bowl-shaped part 3 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 , preferably ultrasonic welding. The concentricity of the two bowl-shaped parts 1 and 2 is hereby 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 or other fixing means 15. 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 the sample withdrawal tubes and the filter 3 are supported by radially extending support webs 18 resp 19. The sample withdrawal tube 17 is terminated inside with a widened cylindrical portion 20 which via the filter presses against a corresponding portion of the sample withdrawal tube 16. As is evident from Figure 2, the sample withdrawal tube 17 is located between four radially directed support webs 19. ALTERNATIVE EMBODIMENTS OF THE INVENTION In Figures 3 and 4 there is shown a modified embodiment of a Y-piece in the connection arrangement according to the invention. The construction corresponds in principle with that according to Figure 1 and 2. Thus the same reference numerals have been used but with the addition of a dash. The most significant difference is that the attachment nipples 5' resp 6' are angularly formed. Furthermore the sample withdrawal tubes 16' and 17' have been given a somewhat different shape. In Figures 5-8 there is shown a somewhat more complete realization of an embodiment of the connection arrangement according to the invention. This also principally corresponds with that which has been described above. Thus the same figure reference numerals are used for corresponding details, but with the addition of a double dash. Reference numerals 5'' resp 6'' thus denotes two nipples which are intended to be attached to an inhalation tube resp an exhalation tube. The bacteria filter itself is denoted by 3''. Reference numeral 14'' denotes a sample withdrawal nipple which is connected to a first sample withdrawal tube 16''. The latter is in turn via the filter 3'' in contact with a second sample withdrawal tube 17''. Reference numeral 4'' denotes a nipple with the aid of which the Y-piece is connected to a patient attachment piece 21''. This is preferably designed substanially in accordance with that described in US-A-4 516 573. It is, however, preferably of uniform thickness. Within the patient attachment piece there is preferably a wad or similar 22'' of a moisture and heat absorbing material which serves to take up heat and moisture from the exhaled gas and pass this to the inhaled gas. Finally in Figure 5, reference numeral 23'' denotes an attachment pipe or cone with the help of which the patient attachment piece 21'' can be connected to a tracheal tube or similar. The Y-piece shown in Figures 5-8 also consists of two bowl-shaped parts 1'' resp 2'' but differs from the above described Y-pieces in that, for example these parts have been given a rounded rectangular shape. Furthermore the attachment nipples 5'' and 6'' are arranged at a different angle to that which is shown in, for example, Figure 3 and 4. Finally, reference numerals 25'' denotes a dome directed towards the interior of the Y-piece in which the sample withdrawal nipple 14'' is arranged. Thanks to this arrangement the Y-piece's inner volume is reduced whilst the sample withdrawal tube 16'' is stabilized. The construction according to Figures 9-12 substantially corresponds with that according to Figures 5-8. Corresponding details have thus been given the same figure reference numerals, but with the suffix a instead of the double dashes used in Figures 5-8. The construction according to Figures 9-12 differs from that according to Figures 5-8 in that the nipples 5a and 6a are arranged parallel to the nipple 4a. Furthermore the fibre wad 22a does not fill the whole patient attachment piece 21a. A free space 24a is left nearest the patient, which is intended to serve as a secretion trap and which 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 directed towards the interior of the Y-piece in which the sample withdrawal nipple 14a is arranged. Thanks to this arrangement the Y-piece's inner volume is reduced whilst the sample withdrawal tube 16a is stabilized. Figures 13-15 are showing a further alternative for the Y-piece made in accordance with the invention. This embodiment corresponds essentially to the one shown in Figures 1 and 2. Different reference numerals have, however, been used, but all with the addition of a'. The Y-piece described comprises two bowl-shaped parts 5a' and 6a' with a bacteria filter 7a' clamped therebetween. The upper bowl-shaped part 5a' is provided with a nipple 1a', which is intended to be connected to a patient attachment piece. The lower bowl-shaped part 6a' is provided with two parallel nipples 2a' and 3a' which are intended to be connected to an inhalation tube resp exhalation tube, which in turn are intended to be connected to a respirator, anaesthesia machine or similar. The bacteria filter 7a' is clamped in the same way as the filter 3 in fig 1. The lower bowl-shaped part 6a' further comprises a sample withdrawal outlet in the form of a nipple 11a'. The nipple 11a' is connected to a first sample withdrawal tube 12a' which in turn, via the filter 7a', is connected to a second sample withdrawal tube 13a'. The main difference between the embodiment according to Figures 1-2 and the one according to Figures 13-15 is that the last mentioned embodiment is provided with a partition wall 4a', preferably made in one piece with the two sample withdrawal tubes 12a' and 13a', separating exhaled gas from inhaled gas. As shown in Figure 15 the part 5a' may also be provided with a support wall 10a' intended to support the filter 7a'.

Claims: Y-piece, for use in a connection arrangement for connecting a patient to a respirator, anaesthesia machine or similar, wherein said Y-piece comprises a sample withdrawal outlet (14) characterized in that a bacteria filter (3) is mounted in said Y-piece substantially perpendicular to the through-flow direction, and that the sample withdrawal outlet (14) is arranged in the exhalation flow direction after the bacteria filter (3) and is connected to a first sample withdrawal tube (16) which extends from the bacteria filter (3) to the outlet (14) and is arranged so as to take bacteria-free samples through said filter (3). Y-piece according to claim 1, characterized in that said first sample withdrawal tube (16) via the bacteria filter (3) is connected to a second sample withdrawal tube (17) which extends from the bacteria filter (3) towards a nozzle (4, 4', 4'', 4a) connectable to a patient attachment piece (21''; 21a) and preferably extends through this nozzle (4) up to and, possibly, into this piece. Y-piece according to claim 2, characterized in that said first and second sample withdrawal tubes (16,17) are arranged on either side of the bacteria filter (3) and are in pressurized contact therewith via an at right angles to the flow direction widened portion, for example a cone-shaped and/or cylindrical funnel-like portion (20). Y-piece according to any of the preceding claims, characterized in that the Y-piece is provided with a partition wall (4a') separating the exhaled gas from the inhaled gas, and extending in the direction towards the patient up to at least the bacteria filter (7a'). Y-piece according to claims 2-4, characterized in that the through-flow area of the Y-piece (1,2) is enlarged in comparison with that of the connectable patient attachment piece. Y-piece according to any of the preceding claims wherein the Y-piece (1,2) comprises three attachment nipples, namely one (4) for the patient attachment piece, one (5) for the inhalation tube and one (6) for the exhalation tube, characterized in that said nipples (4-6) are arranged substantially parallel to each other. Y-piece according to any of the preceding claims, characterized in that the Y-piece's (1,2) through-flow area is maximized in proportion to its volume through a substantially circular form, whilst its length in the flow direction is restricted to that which the function allows. Y-piece according to claim 6, characterized in that the sample withdrawal outlet (14'' or 14a) is arranged, preferably in a form of a nipple, substanially in the middle of the Y-piece (1'', 2''; 1a, 2a) between the attachment nipples (5'', 6''; 5a, 6a) for the inhalation resp exhalation tubes and preferably parallel to these nipples, whereby the sample withdrawal outlet (14'', 14a)has, in a direction perpendicular to its through-flow direction, a somewhat drawn-out through-flow area, for example a substantially oval or rounded-rectangular shaped through-flow area. Y-piece according to any of the preceding claims, characterized in that the Y-piece comprises two bowl-shaped halves(1,2), wherein one or both of said bowl-shaped halves (1,2) are provided with support webs (18,19) for said first and/or second sample withdrawal tube. Y-piece according to claim 9, characterized in that the sample withdrawal outlet (14'', 14a) is arranged in a dome, or similar, directed towards the interior of the Y-piece (1,2) and which is arranged to stabilize the outlet whilst also reducing the inner volume of the Y-piece. Y-piece according to any one of the claims 9-10, characterized in that both bowl-shaped parts of the Y-piece (1,2) are provided with support webs (18, 19) which are so arranged that they disturb the through-flow as little as possible, for example by being radially directed in relation to the principal through-flow direction, whilst also being arranged to support the bacteria filter (3) on both sides. Connection arrangement for connecting a patient to a respirator, anaesthesia machine or similar, comprising a patient attachment piece (21'' or 21a) and a so-called Y-piece (1,2), arranged to join the patient attachment piece to an inhalation resp exhalation tube characterized in that said Y-piece is a Y-piece according to any of the previous claims. Connection arrangement according to claim 12, characterized in that the patient attachment piece (21'' or 21a) is flexible and contains a heat and moisture exchange system in the form of a wad or similar (22'' or 22a) of a flexible material, such as fibers, with the ability to take up heat and moisture from exhaled gas and subsequently deliver this to the inhaled gas, wherein said wad, or similar, (22'', 22a) is impregnated with an antibacterial agent, for example chlorhexidine or hydrogen peroxide, and/or with a hygroscopic substance, such as magnesium chloride, lithium chloride or calcium chloride. Connection arrangement according to claim 13, characterized in that said wad or similar (22'', 22a) consists of fibres of a plastic material having a certain melting point, such as polypropylene, which are coated with another plastic material having a lower melting point, such as polyethylene, with the aid of which the fibres are bonded by heating to said lower melting point. Connection arrangement according to any of the claims 12-14, characterized in that at least one part (24a) of the patient attachment piece (21a) is transparent and no other material is in this part, preferably nearest the patient, so that it can serve as a secretion trap and/or inspection zone. Connection arrangement according to any of the claims 12-16, characterized in that the patient attachment piece (for example 21'' or 21a) is disconnectable from the Y-piece (1,2).

Inventors: KIHLBERG AKE, TRYGGVASON RAGNAR, WIKEFELDT PER, KIHLBERG, AKE, TRYGGVASON, RAGNAR, WIKEFELDT, PER
Applicants: ENGSTROM MEDICAL AB, ENGSTROEM MEDICAL AB
Application year: 1991
Main classification: A61M16
IPC codes: A61M16