in referring to the drawings , and in particular fig1 there is disclosed the transducer or flow tube 1 of this invention shown mounted by insertion within the housing 2 , thereby providing a convenient combination of components that may be easily handled by both the physician and the patient for achieving breath analysis . the transducer 1 may be constructed of any form of polymer , although a transparent material such as methyl methacrylate has been found to be of advantage . in addition , the housing may be constructed of any form of polymer of other material which lends itself to frequent use and handling , while yet maintaining an appearance that is consistent with professional usage . the housing 2 is formed having an upper segment 3 through which is provided longitudinally a series of apertures and through which the transducer 1 may insert , while the lower segment 4 of the housing has smooth curvature flared laterally to facilitate its hand grasping and retention , while interiorly providing ample space for mounting of the various electrical and electronic instrumentalities useful primarily as the means for detecting the functioning of the transducer during usage . by referring also to fig2 and 3 , it can be seen that the transducer desirably has sufficient length to provide for its projection from both ends of the housing , but that proximate its one end it is formed to provide the mouthpiece 5 which is normally disposed for oral grasping by the patient , as during pulmonary testing . an annulus 6 is formed integrally with the flow tube , being spaced a slight distance from its one end to form a limit to the length of the mouthpiece 5 , while said annulus also circumscribes the depth of insertion of the flow tube into the housing upon its encountering a proximate wall of the upper segment 3 of the housing . by referring also to fig4 in addition to fig2 it can be seen that the transducer 1 includes an indexing means 7 , which is in the nature of an integral tab formed upon the surface of the flow tube , with said tab disposed for close contact insertion within a slot 8 formed through the front wall of the housing segment 3 , and in this manner provides a means for insuring that the transducer is properly positioned for accurate usage in the housing 2 . the front end 9 of the index tab 7 is conveniently tapered to facilitate its initial insertion into the said housing and its formed slot 8 . as further seen in fig4 the housing 2 is formed into its two sections 3 and 4 , as previously described , and may include an intermediate wall 10 for segregating the transducer mounting space , as in the section 3 , from the electronic packaging space 11 , as provided in the bottom section 4 of the housing . as shown within the interior of this lower section 4 of the housing , the electronic package , which may include the usual circuit board and other solid state or other form of electronic devices may be conveniently mounted , as at 12 , to the underside of the partition 10 , or may be located at any other convenient position within said lower section 4 . the usual conduit 13 may insert through one end of the section 4 for communication with the electrical package 12 , and provide necessary connection thereto . and , where the transducer is to be utilized for testing other than the lung dead space component or for their closing volume , as for example in the standard nitrogen washout form of other test , then additional instrumentalities customarily used for this latter type of a test may be disposed within this lower section 4 of the housing , and also communicate exteriorly of the same as through the conduit 13 or others . where the instrument is to be utilized for this type of a test , an aperture 14 may be provided through the wall of the flow tube 1 to provide the location where the nitrogen laden breath may be exhaled for eventual confinement and measuring of its nitrogen content . as can further be seen in fig4 a form of diaphragm 15 is suspended within the flow tube of the transducer , and as previously summarized and hereinafter described , is subject to lineal displacement due to the force and pressure of the moving breath there past . one means for detecting this degree of displacement of the diaphragm may comprise a form of electrical core 16 , which is precisely mounted to the intermediate wall 10 of the lower section 4 of the housing , and disposed generally equidistant to either side of the transducer diaphragm 15 . in this particular instance , the core may comprise an e - core , having a pair of electrically conductive coils 17 and 18 provided thereon , and which may be charged with a reference potential for the purpose of inducing the transfer of the magnetic lines of the flux on a path through the various proximate segments of the e - core , in addition to the surrounding environment , particularly thereabove , and within the influence of the said diaphragm . generally , and in the preferred embodiment , a reference potential within the vicinity of 10 volts , peak to peak , and within a range of 5khz frequency has been found useful for this purpose , although other ranges of voltages and frequencies may be useful to provide the same function . as is well known in the art , any for of electrical detecting means for determining the degree of imbalance of the inductances in the two segments of the core may be used for detecting the alternating current output of the core , and which output may be rectified and filtered to provide a direct current output signal that is directly proportional to the displacement of the diaphragm . obviously this output can be correlated to provide a direct readout of the rate of flow and other characteristics of the sample breath , and can be electronically computed and converted into readings for furnishing a direct observation of these results . the preferred style of transducer is shown in fig5 through 7 , wherein the flow tube 1 is shown as being separable into two sections 19 and 20 , the site of the separation being approximately at location where the diaphragm 15 mounts therein , so as to facilitate the manufacture of this device . as shown , one end section of the separated flow tube may have a reduced lip 21 that may insert within the mating end 22 of the other tube section , and in this manner provides means for embracing the periphery of the diaphragm 15 therein , with said tube then being adhesively or otherwise secured together to form an integral transducer . obviously , though , a separable tube is not the only manner for mounting a diaphragm therein . as previously described , the annulus 6 , which acts as a stop means to limit the extent of insertion of the flow tube into its housing , and the index tab 7 , are provided integrally upon the flow tube to regulate its precise positioning within the housing , as during usage . the diaphragm 15 is more accurately shown in fig8 and is formed as a apertured plate 23 useful for partially impeding the flow of breath therethrough so as to induce a slight pressure drop and the incident lineal displacement of the plate under the force of pressure of the breath . this plate may be formed of any type of material that may be reasonably precise and consistent in this degree of displacement with respect to the pressure of the breath it is subjected to , but preferably the plate is constructed of a beryllium copper or perhaps stainless steel , and chemically etched to form uniform apertures therethrough . preferably the plate will have 200 to 500 mesh openings per square inch . hence , the completed plate has the appearance of a foraminous screen , which is milled to those precise tolerances so as to provide consistent readout of information under identical test conditions . the foraminous plate 23 has integrally formed therewith , as around its periphery , a series of acruate shaped arms , the three arms 24 through 26 in this particular design , which integrally connect to the plate at one end , as for example as seen at 27 , while at their opposite ends , as at 28 , they integrally connect with a circumferential ring 29 which is mounted to the interior surface of the flow tube , as for example as previously described with respect to the intermating of the end sections 21 and 22 of the flow tube . on the other hand , many other means for adhesively mounting or adhering the circumferencial ring 29 within the flow tube should be readily apparent . due to the arcuateness of the arms 24 through 26 , it can be seen that the apertured plate 23 is capable of some displacement as pressure is applied to it , which in this particular instance is normally the pressure of the patient &# 39 ; s breath , this deflection sometimes achieving a displacement of approximately one hundred thousandths of an inch , an amount which is easily detectable and measurable by the type of previously described electrical pickup and detecting means . surrounding the periphery of the apertured plate 23 are a pair of rings , as at 30 and 31 , and these rings are secured to the plate at this location by any form of weld or other type of adhesive , and preferably are constructed of ferrous material that provides a more conductive path for transfer of the magnetic lines of flux generated in the e - core . as can be seen , one such ring is mounted to either side of the foraminous plate , and when this partial diaphragm of the transducer is located at the approximate midpoint of the detecting means core , there is provided a balanced relationship between the core inductances indicating a static condition for a null reading . on the other hand , when breath is forced through the transducer and displaces lineally the diaphragm 15 , it can be seen that said diaphragm will be slightly urged in the direction of breath flow , thereby creating a more conductive path for the lines of flux to flow with respect to one end of the e - core than the other , thereby creating an inductance imbalance which is detectable by the usual electrical circuit means , such as from a center tab associated with the core , as is known in the art . this form of diaphragm may be described as a peripherally mounted displaceable diaphragm . as seen in fig9 and 10 , a modified form of the lineal displaceable diaphragm of this invention is shown , and this type of diaphragm is depicted as a centermount form of suspension for the lineally displacable diaphragm . as shown , the transducer or flow tube 32 has formed integrally therein a pair of spaced apart diametral supports 33 and 34 , and which includes a rod member 35 which connects with and spans the longitudinal distance between said two supports . the partial diaphragm 36 is constructed as the type of foraminous screen or plate as previously analyzed with respect to the peripherally mounted diaphragm , but having the rod 35 extending therethrough , and around the periphery of this plate 36 is provided at least one annulus or ring 37 . this ring is constructed preferably of a ferro magnetic material , and functions similarly to the pair of rings 30 and 31 as previously described with respect to fig7 . connecting between the annulus 37 and the rod member 35 are a series of arcuately shaped arms 38 , in this particular instance being three arms , with said arms at their outer ends being secured to the annulus 37 , while their inner ends are secured to the rod member 35 . hence , it can be seen that the force of breath flowing through the flow tube 32 will encounter the foraminous plate 36 and cause its displacement . since this transducer is constructed to the same dimensions that provides for its ease of insertion and location within the housing 2 , as previously described , the degree of displacement of the foraminous plate or diaphragm 36 can be gauged by any form of detecting means , such as the e - core 16 as previously described . another modified form of diaphragm suspension , in this particular instance , also comprising a centermount form of suspension , is shown in fig1 and 12 . in this particular embodiment , the transducer or flow tube 39 incorporates the pair of diametral supports 40 and 41 , which are arranged a fixed distance apart longitudinally of the flow tube , and spanning the distance between said supports is a rod member 42 . mounted for sliding movement upon said rod member is a sleeve 43 , which is conveniently centered upon the rod member by means of a pair of springs 44 and 45 , which normally sustain a stationary position for the slidably sleeve as when the transducer is at rest . extending radially from the sleeve 43 is a foraminous plate or partial diaphragm 46 , constructed of the same material and in the same manner as the plates previously described and analyzed . peripherally mounted circumferentially of said plate in an annulus 47 which is disposed for free sliding movement within the interior of the tube 39 . this annulus may comprise a single or a pair of rings , and is preferably constructed of ferrous material so as to provide a more conductive path for the lines of magnetic flux to flow as during usage of the transducer . once again , the transducer is insertable within a housing as at 2 , and a detecting means such as the e - core 16 of fig4 may be used for determining the degree and extent of lineal displacement of the diaphragm during transducer usage . and , as previously described , any inductance imbalance during usage of the transducer can be detected , measured , and converted by electronic means for providing a direct read out corresponding to the rate or volume of flow , or other measurements , characteristic of the specimen breath . a final modification or variation upon a type of partial diaphragm and detecting means is shown in fig1 . in this embodiment , the transducer or flow tube 48 may incorporate the type of peripherally mounted diaphragm 49 which may be constructed identical with the diaphragm and suspension means 15 as previously analyzed , although the center mount form of suspended diaphragm may also be used in this modified embodiment . in this particular instance , the pair of rings 50 and 51 secure proximate the periphery of the foraminous plate of the diaphragm and function as capacitive plates , and each ring is spaced normally a fixed distance from corresponding capacitive plates 52 and 53 which are also secured rigidly to either the interior of the flow tube , as shown in the drawing , or even can be permanently mounted to the housing and disposed for accommodation of the flow tube therethrough . actually , these capacitive plates 52 and 53 are also constructed in the form of rings . hence , a charge , as from a battery or other electrical source 54 , provides for charging of the respective pairs of plates 50 and 52 , and 51 and 53 , so that when the diaphragm 46 is maintained stationary an equal distance between the two plates 52 and 53 , there will be no capacitive imbalance that is detectable of any measurement . on the other hand , as specimen breath flows through the transducer , thereby causing the diaphragm 49 to lineally displace , its associated capacitive rings 50 and 51 are likewise displaced providing for this capacitive imbalance being detected , measured , and amplified , as at 54 , to provide a readout of information corresponding to the flow of the patient &# 39 ; s breath . it should also be obvious that the principles of this invention can be adapted for use in detecting information about fluid or gas flow in industrial processes . the foregoing provides a description generally of various types of sensitive means for analyzing breath flow , particularly through the lineal displacement of a diaphragm along the longitudinal length of a transducer , which detected information can be converted for readout of pulmonary function information . such information can be analyzed by the physician or technician as an indicator of early warning of lung disease . furthermore , the intergral formation of the transducer of this invention , apart from the detecting means , allows its once use and then disposal . such provides great sanitation in the use of this medical instrument . in addition it is likely that the detecting means may be optically operative , such as through the use of light sensitive diodes , and detect the displacement of the diaphragm in this manner . variations in the type of embodiments shown and described in this invention may occur to those skilled in the art in light of the foregoing disclosure , and such variations as within the spirit and scope of this invention are intended to be protected by any patent to issue hereon . the description of the preferred embodiment in detail is intended for illustration purposes only .
in a pulmonary diagnostic instrument that includes a breath transducer for use in conjunction with the instrumentation for detecting respiratory functioning of a patient or specimen , the transducer comprises a flow tube in which is suspended for lineal displacement a partial diaphragm generally constructed as a foraminous plate , and which during testing , the specimen &# 39 ; s breath flows therethrough to achieve some degree of displacement of said diaphragm . the diaphragm incorporates and operates in association with various ferrous rings for enhancing the transfer of magnetic lines of flux which are generated by a charged e - core for determining the extent of said lineal displacement which is representative of and can be interpreted to provide information pertaining to pulmonary functioning for diagnosis of the respiratory system of the specimen . in another embodiment charged capacitive plates replace the aforesaid ferrous rings and e - core , and through a developed capacitive imbalance caused by the breath induced diaphragm displacement providing information that may be interpretive of pulmonary functioning , or flow of air .