the apparatus arrangement shown in fig1 includes a cpap - unit here generally identified by reference numeral 1 and a humidifying apparatus 2 which can be connected thereto in modular relationship . here the cpap - unit 1 has a substantially block - shaped or box - shaped housing 3 which has a front end face 4 , two side faces 5 , 6 which are arranged in pairs in mutually opposite relationship and which are in substantially parallel relationship with each other , and a rear side 7 which is arranged in the rearward region of the housing 3 in relation to the front end face 4 , as well as an upper top face 8 . provided in the region of the front end face 4 is a connecting device 9 which , in the embodiment illustrated here , has a respiratory gas connecting portion 10 , a pressure - measuring tube connecting portion 11 and an electrical connecting device 12 . the respiratory gas connecting portion 10 and the pressure - measuring tube connecting portion 11 are arranged recessed substantially completely in an opening 13 which is only indicated here . the contact elements of an electrical connecting device 12 are also accommodated in an opening or recess so that those connecting members also do not project or do not project substantially beyond a surface defined by the front end face 4 . in the embodiment illustrated here the front end face 4 is of a slightly curved configuration , thereby affording particularly effective assistance in terms of centering the humidifying apparatus 2 . the respiratory gas connecting portion 10 and the pressure - measuring tube connecting portion 11 are oriented in such a way that they extend substantially parallel to the joining direction which is indicated in simplified form by the arrow 14 . in its bottom region the cpap - unit 1 has support or erection members ( here support feet 15 ) which are such that the connecting members of the connecting device 9 are held at a predetermined vertical heightwise level which is matched precisely to the corresponding heightwise level of the connecting members of the humidifying apparatus 2 . the humidifying apparatus 2 includes a base body 16 and a liquid storage container 17 which is accommodated therein . the liquid storage container 17 can be removed from the base housing 16 for example for refilling it with humidifying liquid . the base housing has a connecting surface portion 18 which is of a correspondingly complementary configuration to the front end face 4 of the cpap - unit 1 and in which are disposed the connecting members described in greater detail hereinafter with reference to fig2 . on a side which is in opposite relationship to the connecting surface portion 18 the base housing 16 is again provided with connecting members which in terms of their structure and their arrangement substantially correspond to the connecting device 9 which has already been described with reference to the cpap - unit 1 . in that way it is then possible for the hose connecting plug provided for example for connection to the cpap - unit 1 also to be connected directly to the humidifying apparatus 2 . in that case connection of the pressure - measuring tube is achieved at the same time . the humidifying apparatus 2 also has support feet 20 which provide that the connecting members on the humidifying apparatus in the region of the connecting surface portion 18 are held at a vertical heightwise level which corresponds to that of the connecting device 9 . as can be clearly seen from fig2 the connecting device 9 on the cpap - unit 1 is of a complementary configuration to the connecting device 21 on the humidifying apparatus 2 . as indicated by the arrows 22 the two connecting devices 9 and 21 can be moved into the joined position in relation to each other . particularly effective pre - positioning of the connecting members , in particular the respiratory gas connecting portion 10 and the corresponding counterpart portion 23 , is achieved in this embodiment by the counterpart portion 23 also being centered by the inside wall 24 of the opening 13 . the respiratory gas connecting portion 10 and the counterpart portion 23 on the humidifying apparatus 2 are disposed at exactly the same vertical heightwise level . provided on the output side of the humidifying apparatus is a connecting structure which in terms of its essential dimensions corresponds to the connecting structure provided on the cpap - unit . the respiration tube connecting plug 25 illustrated here can thus be coupled if required directly to the cpap - unit 1 or to the humidifying apparatus 2 . by virtue of a pressure - measuring connecting conduit which is indicated into the humidifying apparatus , a communication is afforded between the pressure - measuring tube 26 and the pressure - measuring tube connecting portion 11 , when the respiration tube connecting plug 25 is connected to the humidifying apparatus 2 . the cpap - apparatus arrangement described hereinbefore with reference to fig1 and 2 can be used as described in the following example of use . it is firstly assumed that the cpap - unit 1 is already set up on a table top , and now the respiratory gas being conveyed by the cpap - unit 1 is to be humidified . for that purpose , as indicated in fig1 , the humidifying apparatus according to the invention is also set up on the table top and is fitted on to the cpap - unit in a joining direction which is parallel to the surface of the table and substantially perpendicular to the front end face of the cpap - unit 1 . when that is done , the connecting devices 9 and 21 which are provided on the cpap - unit 1 and the humidifying apparatus 2 come together in the joining position . in addition , a voltage supply to a heating device provided on the humidifying apparatus 1 is also afforded by way of an electrical connecting device 12 which is only shown in fig1 . as soon as the two connecting devices 9 , 21 have moved completely into the joined position , the two modules are fixed in that joined position by a latching device ( not shown ) so that the humidifying apparatus 2 is reliably coupled to the cpap - unit . the respiratory gas tube which is originally connected directly to the cpap - unit 1 and which has an integrated pressure - measuring conduit can be connected directly to the humidifying apparatus by way of the respiratory gas connecting plug identified by reference numeral 25 in fig2 . that also affords a corresponding coupling between the pressure - measuring tube 26 and the pressure - measuring tube connecting portion 11 provided on the cpap - unit 1 . for the purposes of introducing humidifying water into the liquid storage container 17 , the latter is removed from the base housing 16 of the humidifying apparatus . after the liquid storage container is filled it can be fitted into the base housing 16 again . the cpap - apparatus system formed from two modules which can be laterally coupled , with a refilling unit which can be removed cartridge - like , is now ready for operation . the view in fig3 shows a longitudinal section through an apparatus for humidifying a respiratory gas ( referred to hereinafter as the humidifying apparatus ), in accordance with a preferred embodiment of the invention . here , the illustrated embodiment of the humidifying apparatus includes a refilling unit 203 which is formed from a trough element 201 and a cup portion 202 coupled thereto and which can be easily removed from a support or installation housing 204 which here is of a multi - part nature . the trough element 201 and the cup portion 202 are coupled together in sealing relationship . the trough element 201 and the cup portion 202 are coupled by way of a sealing structure 206 which , in the embodiment illustrated here , has a first sealing ring 207 and a second sealing ring 208 . the two sealing rings 207 and 208 are accommodated in peripheral grooves provided in a separating element 209 . the separating element 209 has a separating wall 205 which is here of an integral nature . the separating wall 205 separates the internal region of the cup portion 202 from the internal region of the trough element 201 . formed in the cup portion 202 , in conjunction with the separating wall 205 , is a liquid storage space 210 in which initially the predominant part of the liquid provided for humidifying the respiratory gas is stored . formed in the trough element 201 arranged beneath the cup portion 202 is a separate humidifying region in which only a partial amount of the humidifying liquid is accommodated . the level a of the liquid accommodated in the trough element 201 is maintained at a predetermined filling height by way of a quantitative control device . in the course of gradual consumption of the fluid in the trough element 201 , fluid is supplied as a make - up flow successively or continuously from the liquid storage space 210 . a preferred embodiment of a quantitative control device which is provided for that purpose will be described in detail hereinafter with reference to fig3 . here the trough element 201 is of a substantially shell - like nature and has a respiratory gas feed opening 211 and a respiratory gas discharge opening 212 . the respiratory gas which is conveyed by a cpap - unit ( not shown here ) can flow into the trough element 201 by way of the respiratory gas feed opening 211 , according to the respiration activity of a patient . by means of a direction - changing device 213 which is only shown here in simplified form the feed flow of respiratory gas is directed on to the liquid in the trough element 201 . in that situation the respiratory gas supplied thereto is enriched with moisture . the correspondingly humidified respiratory gas can then flow away , by way of the respiratory gas discharge opening 212 . in the embodiment illustrated here the trough element 201 can be heated by means of a heating device 214 . the heating device 214 comprises a heating element which is arranged in the support housing 204 in such a way that the bottom region of the trough element 201 can come into intimate contact therewith . in order to increase the transmission of heat between the fluid in the trough element 201 and the heating device 214 the bottom region 215 of the trough element 201 is formed from a material of high thermal conductivity , for example metal . in the last - mentioned embodiment the above - mentioned bottom region 215 can be formed for example by the insert molding method in the actual main body of the trough element 201 . the trough element 201 is of such a configuration that it can be inserted as an easy fit in self - positioning relationship into the support housing 204 . in that case the respiratory gas feed opening 211 and the respiratory gas discharge opening are aligned with conduits or openings provided in correspondingly complementary manner in the support housing 204 . in the region adjacent to the respiratory gas feed opening 211 the support housing 204 is provided with a connecting portion 216 which , in the embodiment illustrated here , can be fitted directly on to a connecting portion of a cpap - unit , which is of a correspondingly complementary configuration . provided in the immediate proximity of the connecting portion 216 is a further connecting portion 217 which can be coupled to a pressure - detecting connection provided on a cpap - unit . the connecting portion 217 forms part of a conduit system which ultimately communicates with the pressure - measuring connecting portion 218 provided on an opposite side of the humidifying apparatus . in particular a pressure - measuring tube can be connected to that pressure - measuring connection 218 for detecting the pressure in the region of the respiration hose , a gas change valve or possibly also directly in the mask region . beneath the pressure - measuring connecting portion 218 the support housing 204 is provided with a respiration tube connecting portion 219 . the tube connecting members formed at the outlet side on the humidifying apparatus are identical to that of a cpap - unit , in such a way that corresponding connecting tubes or hoses can be optionally connected either directly to the cpap - unit or if necessary , when using the humidifying apparatus , only to the outlet side of the humidifying apparatus 2 . provided beneath the connecting portion identified by reference numeral 216 is a plug connecting device ( not shown here ) by way of which it is possible to make an electrical connection between the heating device 214 and a voltage supply device provided on the cpap - unit . optionally it is also possible for electrical signals , for example pressure - measuring signals , to be transmitted by way of that plug connecting device . the support housing 204 is further provided with a fixing device 220 , by way of which the humidifying apparatus can be mechanically comparatively rigidly coupled to a cpap - unit . a preferred embodiment of a quantitative control device for quantitative metering of the amount of fluid in the trough element 201 will be described hereinafter with reference to fig4 . the liquid storage space 210 and the humidifying region formed in the trough element 201 are separated from each other by way of the separating wall 205 . the fluid stored in the liquid storage space 210 can be passed if required into the humidifying region by way of a fluid conduit device 221 . in this case control of the make - up flow of fluid is implemented by control of the make - up introduction of air into the liquid storage space . in the embodiment illustrated here regulation of the make - up introduction of air is effected by way of a quantitative control conduit device 222 which , similarly to the above - mentioned fluid conduit device 221 , passes vertically through the separating wall 205 . the quantitative control conduit device 222 has a first mouth opening 223 and a second mouth opening 224 . the first mouth opening 223 is arranged at the height of the desired or reference level a . as long as the first mouth opening 223 is closed by the fluid in the trough element 201 , no make - up flow of air can pass into the liquid storage space 210 so that in turn no fluid can flow away out of the liquid storage space 210 by way of the fluid conduit device 221 . as soon as the level a falls below the level of the first mouth opening , a make - up flow of air can pass into the liquid storage space , whereby in turn fluid can pass out of the liquid storage space 210 into the trough element 201 or the separate humidifying region formed therein . the fluid conduit device 221 has a discharge mouth opening 225 which is somewhat below the reference level identified here by the letters a . in the embodiment illustrated here the fluid conduit device 221 , the quantitative control conduit device 222 and the separating wall 205 are formed by an integral member . for the purposes of introducing the liquid into the liquid storage space , it is possible for that integral member to be withdrawn from the cup portion 202 . the cup portion 202 can optionally also be provided with a corresponding refilling opening which can be sealingly closed . the cup portion 202 , the integral member having the separating wall and the trough element can each be cleaned separately . the quantitative control conduit device 222 is of such a design configuration that the second mouth opening 224 provided thereon is above the maximum filling level of the liquid storage space 210 . fig5 is a perspective view of the humidifying apparatus described hereinbefore with reference to fig3 and 4 . the cup portion which is preferably formed from a transparent material can be seen here in the form of a bowl of substantially cylindrical configuration . that bowl is fitted in a receiving portion which is also cylindrical and which is formed in the support housing 204 . in the region of the cup portion 202 the support housing 204 is of such a design configuration that the cup portion can be gripped with one hand . the connecting portion 217 and the pressure - measuring connecting portion 218 which have already been described with reference to fig3 are provided in the region of the rear side 226 of the humidifying apparatus . provided beneath those connecting portions is the fixing device which is identified by reference 220 in fig3 and which can provide particularly rigid coupling of the humidifying apparatus to a corresponding cpap - unit . provided in a receiving recess beneath the connecting portion 216 is an electrical plug connecting arrangement ( not shown here ) for providing an electrical connection for the heating device to the associated cpap - unit . provided in the lateral region of the outer housing are switch members 227 , by way of which it is possible to set on the one hand the temperature of the liquid in the trough element 201 and the switch - on time for the humidifying apparatus . the rear side 226 of the humidifying apparatus is of a configuration corresponding to the front side of a cpap - unit described hereinafter with reference to fig6 a so that the humidifying apparatus can be connected in a modular manner virtually without any intermediate space to the cpap - unit . the cpap - unit shown in fig6 a has a substantially cuboidal housing , in the upper region of which is provided a gripping arrangement 330 , by way of which the cpap - unit can be gripped in an ergonomically advantageous manner . provided in a front end region are connecting members 331 , for the connection of at least one respiration tube or hose . the illustrated embodiment has a respiration hose connecting projection 332 and a pressure - measuring tube connecting projection 333 . the arrangement of those connecting members substantially corresponds to the arrangement of the connecting members 216 and 217 described with reference to fig3 . the connecting members 231 are further of such a configuration that the connecting members 216 , 217 on the humidifying apparatus ( fig3 ) can be directly fitted on or fitted in . also provided in the bottom region of the cpap - unit are engagement structures which can be brought into engagement with engagement portions of a complementary configuration , on the humidifying apparatus . the connecting members 331 are here arranged in recessed relationship in such a way that they do not project beyond an outside surface and in particular a front surface of the housing . fig6 b shows the humidifying apparatus described hereinbefore with reference to fig3 and 5 , viewing on to the front region thereof . the connecting portions 216 and 217 are arranged in recessed relationship , similarly as also in regard to the cpap - unit . the connecting portions are surrounded by a plug - receiving space 234 into which can be inserted a plug preferably formed from a soft material , in particular silicone rubber . the plug - receiving space 234 is preferably of such a nature that a corresponding plug slides both on the respective projection 216 , 217 and also along the wall of the plug - receiving space 234 . the invention is not limited to the embodiments by way of example described hereinbefore . for example it is also possible for the described humidifying apparatus to be integrated directly into a corresponding cpap - unit . it is also possible to fit into the support housing which can be docked in a simple fashion to a cpap - unit , refilling units which deviate in respect of their structure and the humidifying principle involved , from the described humidifying apparatus . it is also possible for the trough element of the humidifying unit to be so designed that it can be connected directly to the cpap - unit , omitting the support or installation housing . the described humidifying apparatus can also be connected to a respiratory gas source , with the interposition of a hose conduit . the refilling unit can also be arranged in the form of a substantially trough - like unit under the cpap - unit . the respiration tube or hose 301 shown in fig7 is provided in its end region with a connecting device 302 which here has a base body 303 formed from an elastomer material , in particular silicone rubber , with two coupling portions 304 , 305 formed therein . the two coupling portions 304 , 305 are formed integrally by mutually parallel tube zones which are of circular cross - section . the inside diameter of the respective tube zone is slightly smaller than the outside diameter of the connecting projections which pass into the two tube zones when the plug is connected thereto and in that case is slightly enlarged . formed in the region of the base body , which is towards the hose or tube , is a fixing portion 306 in which the respiration tube 301 is fixed by way of a ring element 307 . the ring element 307 is here also formed from an elastomer material and is secured by adhesive to the outside surface of the respiration tube . an additional tube — here a pressure - measuring tube 308 — is guided in the interior of the respiration tube 301 . the pressure - measuring tube 308 opens into the coupling portion 305 by way of a passage duct 309 formed in the base body 303 . the pressure - measuring tube 308 is secured by adhesive or vulcanisation in the base body 303 . the passage duct 309 is of such a configuration that the pressure - measuring tube 308 is only slightly curved . the angle α between the longitudinal center line of the coupling portion 304 and the longitudinal center line of the passage duct 309 is preferably less than 35 °. the transition of the inside wall of the pressure - measuring tube 309 into the coupling portion 305 is effected here substantially steplessly . a corresponding shoulder 310 is provided at the end of the passage duct 309 , for that purpose . the respiratory gas conduit region 311 formed in the base body 303 in this case also forms a substantially stepless transition into the inner region of the respiration tube 301 . with suitable elasticity of the tubes 301 , 308 , it is possible for them to be passed to the end face 312 of the base body 303 so that the coupling members on the unit side can pass directly into the tubes 301 , 308 . the external configuration of the base body shown in fig7 will be described in still greater detail with reference to fig8 a and 8 b . as can be clearly seen in particular from fig8 a , the coupling portion intended for the connection of the additional tube is arranged at a radial spacing from the respiratory gas conduit coupling portion 304 in a region 314 of the base body 303 , which projects radially outwardly in a nose - like configuration . that provides for effective preliminary positioning of the base body in a recess provided in the unit . that region which extends radially outwardly in a nose - like configuration decreases continuously towards the end of the base body 1 , which is towards the respiration tube . provided in the region of the end towards the tube is a peripheral bead or ridge 315 , by way of which a flow of forces between the hose and the plug structure , which is advantageous from mechanical points of view , is achieved . fig9 , for explanatory purposes , shows a preferred embodiment of a connecting structure on the unit , which connecting structure is of a substantially complementary configuration to the coupling portions 304 , 305 provided in the base body 303 of the plug . the projection portion which is identified here by reference 316 passes into the coupling portion 304 in the joined position of the assembly . the projection portion identified by reference numeral 317 comes into engagement with the coupling portion in the joined position . the two projection portions 316 , 317 are arranged in recessed relationship in a recess 318 . the inside wall which defines the recess 318 , in conjunction with the external contour of the base body 303 shown in fig8 a , provides for pre - positioning thereof . the connecting structural component shown in fig1 includes a respiratory gas conduction device which is here in the form of a tube projection portion 401 . a further tube projection portion 402 is arranged adjacent to that tube projection portion 401 , leaving an intermediate space . the tube projection portion 402 forms a pressure - measuring tube connecting device . the two tube projection portions 401 , 402 are arranged in recessed relationship in a recess 403 . that recess is surrounded by a front cover plate 404 . the cover plate 404 and the wall defining the recess 403 are formed in one piece . in a region remote from the end of the tube projection 401 , which is towards the tube , it opens into a base plate 405 which here forms a cover plate for a labyrinth arrangement . this labyrinth arrangement which is not described in greater detail here forms a prolonged respiratory gas guide path for the absorption of any odors produced by a blowing device . the base plate 405 is coated with a sound - absorbing material , in particular foam , on the rear side which is not visible here . provided in a region between the base plate 405 and the cover plate 404 is a connecting duct 406 , by way of which the interior of the tube projection 402 can be coupled to a pressure transducer arranged on a control board . the connecting structural component is further provided with fixing devices 407 , 408 , by way of which that component can be fixed in a cpap - unit in an easily interchangeable manner . more particularly but not exclusively the conduit devices shown in fig1 a , 11 b and 11 c can be connected to the illustrated connecting structural component . in this respect fig1 a shows a compact plug which is advantageous in terms of handling , from ergonomic points of view , with an integrated pressure - measuring tube passage configuration . fig1 b shows a respiration tube 409 and a pressure - measuring tube 410 which is independent thereof , both of which can be connected without a plug arrangement directly to a corresponding cpap - unit , by way of the connecting structural component according to the invention . fig1 c is a greatly simplified view showing a coupling portion of a humidifying apparatus which can be fitted directly to a cpap - unit by way of the structural component according to the invention . in that case the projection portion identified by reference numeral 411 engages with the tube projection 401 and the bore portion 412 with the tube projection 402 .
an apparatus for delivering pressurized , humidified breathable gas to a patient having a sleep - related disorder includes a cpap unit with a blower configured to generate a flow of pressurized breathable gas . the apparatus also includes a liquid storage container configured to hold a body of liquid . the liquid storage container has a gas feed opening , a gas discharge opening and a humidifying region above a metallic heat conducting material . in addition , the apparatus includes a support housing integrated directly into the cpap unit and having a receiving space configured to removably receive the liquid storage container . the liquid storage container is structured such that when the liquid storage container is received by the support housing , the gas feed opening aligns with and engages with an ending portion of a gas feed flow path defined by the support structure and the gas discharge opening aligns with and engages with a beginning portion of a gas discharge flow path defined by the support structure so that the liquid storage container fluidly connects the gas feed flow path and the gas discharge flow path .