Abstract:
Ear canal caloric testing apparatus includes an ear mold to which a distensible balloon-like receptacle is secured for containing pressurized calorized fluid. Vent passages are provided in the ear mold externally of the receptacle for venting trapped air from the ear canal when the receptacle is distended.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to improvements to the Foti probe described in my U.S. patent application Ser. No. 926,718, filed July 21, 1978, entitled &#34;Closed Flow System Method and Apparatus For Inducing Nystagmus,&#34; which is a continuation of application Ser. No. 771,340, filed Feb. 23, 1977, now abandoned. 
     In my aforesaid patent application I describe a membrane-like probe having a flow-through path for nystagmus-inducing liquid, the probe expanding when filled with such liquid to conform to the contours of the ear canal. In one embodiment the insertion depth of the probe is standardized by an ear mold having a widened stop member which limits insertion by abutting the tragus. In order to prevent air from being trapped in the ear canal by the expanding probe, a vent tube extends through the length of the probe to a bore defined through the ear mold. 
     I have found that the vent tube unnecessarily complicates the construction of the probe and it is an object of the present invention to eliminate the vent tube while still preventing air from being trapped in the ear canal by the expanding membrane. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, one or more bores or channels are defined in the ear mold to provide venting of the ear canal via the ear mold rather than through the membrane portion of the probe. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and still further objects, features and advantages of the present invention will become apparent upon consideration of the following detailed description of one specific embodiment thereof, especially when taken in conjunction with the accompanying drawings, wherein: 
     FIG. 1 is a view in perspective of the improved probe of the present invention; 
     FIG. 2 is a view in section taken along lines 2--2 of FIG. 1; 
     FIG. 3 is a view in section taken along lines 3--3 of FIG. 2; and 
     FIG. 4 is a partially-cut view in perspective of a modified embodiment of the present invention. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     For purposes of simplification of the present invention, my aforesaid U.S. patent application Ser. No. 771,340 is incorporated herein by reference. 
     Referring specifically to FIGS. 1 through 3 of the accompanying drawings, an improved probe is designated generally by the reference numeral 10. Probe 10 includes an ear mold 11 comprising its rearward end and a balloon-like member 12 comprising its forward end. Although preferably formed as an integral member, such as by injection molding techniques or the like, ear mold 11 is described herein as comprising multiple longitudinally-oriented sections. The rearward-most section 13 is, by way of example only, generally cylindrical, with two longitudinally-extending bores 14, 15 defined therethrough. A stop member 16, in the form of an annular flange, extends radially from the forward end of section 13. Immediately forward of stop member 16 is another longitudinally-extending section 17 (cylindrical in the illustrated embodiment) having generally the same diameter as section 13. Extending forwardly of section 17 is the forward-most section 18 of ear mold 11, section 18 also being cylindrical, by way of example only, with a somewhat smaller diameter than section 17. An annular shoulder 19 defines the transition between sections 17 and 18. 
     A longitudinally-extending bore 20 is defined from the forward end of ear mold section 18 rearwardly through the centers of sections 18 and 17. The forward ends of bores 14 and 15 terminate as openings in the rear wall of bore 20. A flow divider 21 of generally rectangular configuration extends longitudinally through bore 20 to isolate bores 14 and 15 from one another throughout the length of bore 20. 
     A plurality of longitudinally-extending channels 22 are defined in the surface of ear mold sections 13 and 17. Each channel 22 extends forwardly from section 13, through the base of stop member 16, to section 17 and terminates at annular shoulder 19, thereby providing a flow path from shoulder 19 to rearwardly of the stop member for purposes to be described below. 
     Flow tubes 23 and 24 are inserted into the rearward ends of bores 14 and 15, respectively. The tubes may be press-fit or adhesively or otherwise secured in the bores. Tubes 23 and 24 serve as inlet and outlet tubes for nystagmus inducing fluid as may be delivered from a suitable pump. An example of such a pump is described in U.S. patent application Ser. No. 762,437, filed Jan. 24, 1977, by George Foti, and entitled &#34;Pump For Closed Circulation System.&#34; 
     Membrane-like balloom member 12 is secured about forward ear mold section 18 and extends forwardly thereof. The open end of the balloon member may be stretch-fitted about section 18 so that member 12 can be disposed of after use and replaced with another balloon member. Alternatively, the balloon member 12 may be permanently secured to section 18, as by adhesive or the like, whereby the probe would be sterilized before re-use. The dimensioning of the balloon member 12 and sections 17 and 18 of the ear mold 11 is such that when member 12 is fully inflated by liquid and the forward end of stop member 16 rests against the tragus of the ear, the inflated member 12 conforms to the external auditory canal and tympanic membrane of the ear. 
     In operation, nystagmus-inducing liquid flows through inlet tube 23 in bore 14 to one side of bore 20 and is directed by flow divider 21 to membrane 12. Return flow is directed back through the other side of bore 20 to outlet tube 24. Depending upon the temperature of the liquid, thermal transfer from the liquid to the auditory canal is effected through the thin membrane material of member 12 to induce nystagmus in the patient as described in my aforesaid patent application. 
     The feature of the present invention is the presence of vent passages 22 defined entirely in the ear mold 11. More particularly, when the probe is inserted in a patient&#39;s ear, a volume of air is trapped in the ear. This is true if the probe is inserted with member 12 inflated or deflated. Vent passages 22 provide an exhaust path for the trapped air, thereby permitting member 12 to conform fully to the auditory canal and preventing injury to the patient due to pressure build-up. By providing the vent passage in the ear mold only, rather than in the balloon member 12, the configuration of the balloon member is much simpler and the overall probe can be manufactured at less cost. 
     The vent passages may be defined in the ear mold in other ways than shown in FIGS. 1-3. The important point is that the vent passage is defined only in the ear mold and not through member 12. An example of another approach to forming the vent passages is shown in FIG. 4. Specifically probe 30 has elements which are identical to those in probe 10 and are designated by the same reference numerals. The difference resides in the fact that the longitudinal vent passages are not defined in rearward section 13. Instead, vent passages 32 are defined longitudinally along section 17 and extend radially along the forward surface of stop member 16, terminating in an annular channel 33 which is disposed concentrically near the outer edge of the stop member. Stop member 16 in probe 30 is provided with a slight rearward taper so that only the base of that member abuts the patient&#39;s tragus while the radially outer portion is separated from the tragus. Air trapped by the probe in the patient&#39;s ear can therefore escape by travelling along passages 32 to annular channel 33 which communicates with ambient. 
     While I have described and illustrated one specific embodiment of my invention, it will be clear that variations of the details of construction which are specifically illustrated and described may be resorted to without departing from the true spirit and scope of the invention as defined in the appended claims.