Abstract:
The benefits of rapid modeling and prototyping of a hearing instrument housing can be increased by fashioning the housing as a monolithic unit, incorporating the faceplate as an integral part of the housing. An opening in the faceplate region of the housing can be created to accept a module containing various electronic components of the hearing instrument.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation-in-part of U.S. patent application Ser. No. 09/887,939 filed Jun. 22, 2001, incorporated by reference herein. 
    
    
     BACKGROUND AND SUMMARY OF THE INVENTION 
     The procedure for fabricating a hearing instrument using rapid prototyping methods is described in the patent application noted above. In that application, reference is made to an integral faceplate. Instead of a separately fabricated element, the hearing instrument housing can be fabricated as a monolithic unit having an integral faceplate, such that the faceplate is no longer a separate element. The housing would have an opening in the vicinity of the location where a faceplate would otherwise be attached and a module, containing the various electrical components of the instrument, would be inserted in the opening. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a drawing of a monolithic hearing instrument housing; 
         FIGS. 2 and 3  are drawings of a component module for the hearing instrument housing of  FIG. 1 ; 
         FIG. 4  illustrates the co-location of a component module and a mating receptacle with respect to a hearing instrument shell; 
         FIG. 5  is a drawing of a mating receptacle for the component module; 
         FIG. 6  illustrates the hearing instrument shell of  FIG. 4  and the mating receptacle; 
         FIGS. 7 and 8  illustrate the co-location of the receptacle for the component module with respect to the hearing instrument shell and a grid of radial lines for completing the fabrication of the hearing instrument housing; 
         FIGS. 9 and 10  illustrate a grid of radial and contour lines for completing the fabrication of the hearing instrument housing; 
         FIG. 11  illustrates a partially-complete hearing instrument housing; 
         FIG. 12  illustrates a complete hearing instrument housing with a component module inserted therein; 
         FIG. 13  is a flow chart of a process for fabricating a hearing instrument housing; and 
         FIG. 14  is a flow chart of a process for creating a transition surface between a hearing instrument shell and a receptacle in the faceplate of the hearing instrument. 
     
    
    
     DESCRIPTION OF THE INVENTION 
     As discussed in detail in U.S. application Ser. No. 09/887,939, a hearing instrument housing or body  10  can be manufactured using rapid prototyping or direct manufacture techniques. One portion of the housing  10 , a shell  20 , partially resides in the concha or bowl of the ear—the area just outside of the ear canal. Depending on the type of instrument (completely within the ear canal, extending partially out of the canal, or occupying more of the outer ear, as discussed in U.S. application Ser. No. 09/887,939), the shell  20  may extend into the concha or barely extend into the ear canal or reside completely within the ear canal. 
     The shell  20  conforms to the user&#39;s ear canal and optionally a portion of the ear external to the ear canal. It may be created from a digital representation obtained by directly scanning the user&#39;s ear canal and, to the extent necessary, any portion of the ear external to the ear canal, or an impression of the desired portion of the ear. 
     The remaining portion of the housing  10 , the faceplate or outer section  30 , is oriented to the outside and constitutes in part the outwardly-visible portion of the hearing instrument. Because it is largely exposed to the outside, the outer section  30  can assume any desired shape and contour. Finally, there is a vent  40 , which allows air flow through the hearing instrument. 
     A component module  100  for the housing  10  is shown in  FIGS. 2 and 3 . As noted previously, it may contain a microphone, battery, and an amplifier. A volume control  120 , a push button  122 , a microphone port  124 , and a battery door  130  are visible in  FIG. 2 , illustrating the surface of the module  100  oriented to the outside of the housing  10 .  FIG. 3  illustrates the “internal” or “underside” view of the module  100 , showing a battery  140 , a microphone  150 , an amplifier  160 , and programming contacts  190 . The module  100  has a base  170  that may be provided with a rounded or beveled edge  172 . 
       FIGS. 2 and 3  illustrate just one selection and arrangement of components; other combinations and arrangements of components, internal and external, could be used as desired. The module  100  can assume any desired shape and dimensions necessary to accommodate the components employed, taking into account the shape and size of the housing  10 . 
     The module  100  provides a reference structure for creating a surrounding receptacle  200  in the housing  10  into which the module  100  is inserted after the housing  10  has been completed (see the receptacle illustrated  200  in  FIGS. 4 and 5 ). Thus, the exterior of the module  100  and the interior of the receptacle  200  will have complementary mating features. Although it appears to be a separate element in the figures, the receptacle  200  will be an integral part of the housing  10  after fabrication has been completed. 
     Given the module  100  illustrated in  FIGS. 2 and 3 , with a vertical peripheral wall  110  having a height  112  that varies along the periphery of the module  100 , the receptacle  200  will have a corresponding inner wall  202 , as shown in  FIG. 5 . The dimensions of the interior surfaces of the receptacle  200  can be slightly larger than the module  100  to allow insertion into the receptacle  200  without excessive force. 
     Working with the digital representations of the shell  20  and the module  100 , the module  100  and the mating receptacle  200  are positioned in three-dimensional space where desired relative to the shell  20  of the hearing instrument housing  10 , as illustrated in  FIG. 4 . This can be at any location, bearing in mind that the components on the component module  100  must clear the inside of the housing  10 . One of the larger components is the battery  140 , which in this figure protrudes downwardly. Also visible in this view are the microphone  150  and the amplifier  160 . This clearance with respect to the housing  10  may be assured by using a collision avoidance technique such as that discussed in U.S. application Ser. No. 09/887,939. 
     As shown in  FIG. 5 , a ledge  204  may be provided around the inside base of the receptacle  200  to provide a seat for the base  170  of the module  100  (see  FIG. 3 ). Protruding from the base  170  are one or more spring latches  180  which secure behind the ledge  204  of the receptacle  200 . Although four such latches  180  are shown in  FIG. 3 , the actual number employed is a matter of design choice. A rounded or beveled edge  172  of the module  100  facilitates easier insertion and seating in the receptacle  200 . As an additional enhancement, the ledge  204  may have downward extensions  206  to allow for latches  180  of longer length and greater spring action. 
     The housing  10  is then completed by extending the rim  22  of the shell  20  towards the receptacle  200  ( FIG. 6 ). (Alternatively, the receptacle  200  could be extended towards the shell  20 .) The shell  20  and the receptacle  200  are thus merged, to create the outer section  30  between the shell  20  and the receptacle  200  (see  FIG. 1 ). This outer section  30  may be curved to provide a smooth transition surface from the shell  20  to the receptacle  200 . The foregoing process for fabricating a hearing instrument housing is set forth in the flow chart in  FIG. 13 . 
     One method of achieving this transition is to subdivide the region  300  between the shell  20  and the receptacle  200  ( FIG. 6 ). This can be done by extending radial lines  310  from the shell rim  22  to the receptacle  200  (see  FIGS. 7 and 8 ), creating a series of segments  320 . The radial lines  310  may be straight lines, elliptical curves, or any other suitable curve. 
     The segments  320  could then be divided by drawing a series of graduated transverse contours  330  that span the region  300  from the receptacle  200  to the shell rim  22  (see  FIGS. 9 and 10 ). The contours  330  near the receptacle  200  would conform to the periphery of the receptacle  200  while those nearest the rim  22  would conform to that shape. The number of radials  310  and contour lines  330  can be as many as necessary to achieve the desired smoothness of the surface between the shell  20  and the receptacle  200 . 
     The grid of radials  310  and contour lines  330  provides a framework for filling in the housing  10  using the rapid prototyping process discussed in U.S. application Ser. No. 09/887,939. he process of gradually completing the housing  10  is illustrated in  FIG. 11  and a completed housing  10  is shown in  FIG. 12 . When fabricated, the housing  10  can have a thickness in the vicinity of the receptacle  200  generally equal to the height of the receptacle  200 . 
     When the region  300  is fabricated, allowance must be made for the vent  40 , also visible in  FIGS. 7–12 . Thus, the surface must also provide an opening to allow for a continuation of the vent  40  to the outside. 
     As can be seen from  FIGS. 4 ,  7 ,  8 , and  10 , the melding of the shell  20  and outer section  30  could result in a sharp edge at the rim  22 . Thus, an intermediate transition surface  340 , such as a bevel, fillet, chamfer, or some other modification can be fashioned at the junction of these two components. The foregoing process for creating a transition surface between a hearing instrument shell and a receptacle in the faceplate of the hearing instrument is set forth in the flow chart in  FIG. 14 .