Abstract:
A disposable diaphragm assembly for use with al types of conventional stethoscopes and a universal retainer ring for retro-fitting conventional stethoscopes to accept the disposable diaphragm assembly. A novel stethoscope for use with the disposable diaphragm assemblies. A stationary dispenser for the disposable diaphragm assemblies from which the assemblies may be loaded onto either retrofitted conventional stethoscopes or the novel stethoscope of this invention without the assembly being contaminated by the hands of medical personnel. Portable and disposable dispensers which also provide for the loading of the disposable diaphragm assembly in a manner which prevents the assembly from becoming contaminated by the hands of medical personnel.

Description:
This application is claiming the benefit of provisional application No. 60/138,765 filed on Jun. 11, 1999. 
    
    
     FIELD OF INVENTION 
     This invention relates to disposable diaphragm assemblies for stethoscopes used in the prevention of the spread of infectious diseases through the use of stethoscopes. More particularly, the present invention relates to both existing stethoscopes which may be retrofitted for the use of disposable diaphragm assemblies and to novel stethoscopes which have a main housing or body prepared for the use of the disposable diaphragm assemblies. The present invention also relates to dispensers, both stationary and portable, for the disposable diaphragm assemblies. 
     BACKGROUND OF THE INVENTION 
     Most common stethoscopes are designed with a retainer ring to hold a diaphragm in place. One such prior art stethoscope design is shown in FIGS. 1 and 2. The retainer ring  1  is attached to the stethoscope head  2  by means of threads  5 . The retainer ring  1  is circular in shape having a vertically oriented side portion  4 , the inside surface of which is threaded. Molded onto or attached onto the bottom face of such side portion  4  is a horizontally oriented lip portion  3  which extends toward the center of the circular retainer ring  1 . A diaphragm  7  is held in place between lip portion  3  and the stethoscope head  2  upon threading or clipping the retainer ring  1  onto the stethoscope head  2 . FIG. 3 shows an alternative prior art stethoscope design in which an O-ring  6  is used to hold the retainer ring  1  onto the stethoscope head. In each of these prior art devices, the diaphragm is changed by removing the retainer ring, removing the old diaphragm placing a new diaphragm in the retainer ring and re-attaching the retainer ring, Standard non-disposable diaphragms are generally not replaced between use on patients due to the time required to undertake such a change. As an alternative, the stethoscope head and diaphragm may be cleaned between uses. Such cleaning, however, may be detrimental to both the structural integrity and acoustical accuracy of the diaphragm, as such cleaning is often done with alcohol swabs. That is, both the difficulty in changing out diaphragms and the potential harm inflicted on diaphragms by cleaning act as barriers to the use of clean, uninfected stethoscope diaphragms. 
     The possibility of the transmission of infection between patients, where the stethoscope acts as the source of infection, is recognized in the medical community and is the subject of articles such as “Contaminated Stethoscopes: A Potential Source of Nosocomial Infections” by Mangi et al, Yale Journal of Biology and Medicine, 45,600-45,604 (1972) and “Contaminated Stethoscopes Revisited” by Melinda A. Smith, MPH, et al, Archives of Internal Medicine, Vol. 156 (1996). 
     A removable stethoscope diaphragm is the subject of U.S. Pat. No. 4,867,268 to Izaak Alan Ulert. It comprises a disposable diaphragm which replaces the diaphragm already in place on conventional stethoscopes. U.S. Pat. No. 4,461,368 to Plourde describes a diaphragm cover which is used for the prevention of the spread of infection from contaminated stethoscopes. The disposable diaphragm of the &#39;368 patent interposes a second layer of material between the source of sound and the ear, which has the potential of diminishing or distorting the sound. Furthermore, the disposable diaphragm of the &#39;368 patent is not easily or quickly interchanged. The lack of ease of use acts as a disincentive to use. 
     Completely disposable stethoscopes are also currently available. Such stethoscopes, however, do not offer the acoustic quality obtainable with standard stethoscopes. Dedicated stethoscopes are fairly expensive, thereby motivating repeated use which defeats the intended safety features. 
     There is a need, therefore, for a stethoscope device which provides high-quality acoustic performance in conjunction with an economical means of providing uninfected contact with each patient. Furthermore, there is a need that such device offer medical personnel ease of use with little or no preparation time. 
     SUMMARY OF THE INVENTION 
     The present invention addresses the shortcomings of the prior art devices by providing disposable diaphragm assemblies with acoustic performance which is equal to or greater than that of conventional stethoscopes. The present invention does not use a cover over the existing diaphragm of a conventional stethoscope as in the &#39;368 patent. Therefore, the acoustic quality remains high and there is no additional sound attenuation which is present when multiple layers are placed between the source of the sound and the ear. 
     The disposable diaphragm assemblies of the present invention are inexpensive and therefore, may be changed out between uses so that only clean and uninfected portions of the stethoscope come into contact with a patient. The present invention also addresses the cleanliness and infection issue by providing dispensers for the disposable diaphragm assemblies which permit the disposable diaphragm assemblies to be attached to a stethoscope without contacting the diaphragm assemblies. Therefore, germs and contaminants are not transferred from the hands of medical personnel to patients. 
     The present invention provides means for retrofitting existing stethoscopes, including standard and open bell or pediatric stethoscopes. In addition, the present invention provides a novel stethoscope which may also be used with the disposable diaphragm assemblies of the present invention. 
     The present invention includes disposable diaphragm assemblies made of any suitable material, such as but not limited to plastic, rubber or other materials and dispensers stationary or portable, for such disposable stethoscope diaphragms. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES 
     FIG. 1 is a perspective top view of a prior art stethoscope head and retainer ring design. 
     FIG. 2 is a partial cross-sectional view along the axis A-B of FIG. 1 of a prior art stethoscope head and retainer ring design. 
     FIG. 3 is a partial cross-sectional view along the axis A-B of FIG. 1 showing an alternative prior art stethoscope and retainer ring design. 
     FIG. 4 is a partial cross-sectional view of the preferred embodiment of the universal retainer ring of the present invention. 
     FIG. 5 is a partial cross-sectional view of an alternative embodiment of the universal retainer ring of the present invention. 
     FIG. 6 is a top perspective view of the preferred embodiment of the holding ring of the disposable diaphragm assembly of the present invention. 
     FIG. 7 is a partial cross-sectional view of the preferred embodiment of the disposable diaphragm assembly of the present invention. 
     FIG. 8 is a partial cross-sectional view of the disposable diaphragm assembly of the present invention attached to a stethoscope head having a universal retainer ring of the present invention. 
     FIG. 9 is a side view, partially cross-sectioned, of a prior art combination standard and open bell stethoscope. 
     FIG. 10 is a partial side view, partially cross-sectioned, of a prior art open bell head and a ring type protective cover of the present invention. 
     FIG. 11 is a side view, partially cross-sectioned, of a novel stethoscope head, constructed for use with the disposable diaphragm assembly of the present invention. 
     FIG. 12 is a side view, partially cross-sectioned, of a combination standard head and open bell head of the present invention and protective cover of the present invention. 
     FIG. 13 is a perspective view of a preferred embodiment of the disposable, portable dispenser for the disposable diaphragm assembly of the present invention. 
     FIG. 14 is a side partial cross-sectional view, taken along the axis A—A of FIG. 13, of the portable, disposable dispenser of the present invention. 
     FIG. 15 is a perspective view of a preferred embodiment of the portable, disposable dispenser of the present invention illustrating a break in the topmost scored ring. 
     FIG. 16 is a perspective view of an alternative embodiment of the portable, disposable dispenser of the present invention. 
     FIG. 17 is a top view of the preferred embodiment of the stationary dispenser of the present invention. 
     FIG. 18 is a cross-sectional view, taken along line A—A of FIG. 17, of the stationary dispenser of the 
     FIG. 19 is a perspective view of the stationary dispenser of the present invention. 
     FIG. 20 is a cross-sectional view, taken along line B-B of FIG. 17 of the détente pin and recess of the stationary dispenser of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring first to FIG. 4, the present invention utilizes a universal retainer ring  8  which is attached to a stethoscope head  2  from which its original retainer ring has been removed. The universal retainer ring  8  is circular in shape. Universal retainer ring  8  does not have the horizontally oriented lip portion present in retainer ring  1  described in connection with FIGS. 2 and 3. Where the original retainer ring was of the type shown in FIG. 2 which was attached to the stethoscope head by means of threads, the inside surface of the universal retainer ring  8  is threaded so as to attach onto the corresponding stethoscope head  2 . Universal retainer ring  8  is sized such that the protrusion  16  on the stethoscope head  2  lies slightly below the bottom edge  9  of the universal retainer ring  8  when placed into position on stethoscope head  2 . 
     FIG. 5 shows an alternative embodiment of the universal retainer ring  8  which may be used for stethoscopes originally fitted with retainer rings of the type shown in FIG. 3 in which an O-ring is used to attach the retainer ring  1  onto the stethoscope head  2 . As seen in FIG. 3, the inside surface of the illustrated universal retainer ring contains a semi-circular indentation  6 A into which the O-ring  6  fits. It will be understood that the inside portion of the universal retainer ring  8  may be of any shape or configuration necessary to allow the universal retainer ring  8  to be fitted onto any existing stethoscope head  2 . The embodiments shown in FIGS. 4 and 5 correspond to the most common currently available stethoscope designs. 
     Each embodiment of the universal retainer ring is equipped with a radial outwardly protruding tab  10  which is formed by outwardly and upwardly tapered portion  11  and outwardly and downwardly tapered portion  12 . Tab  10  is used to hold the disposable diaphragm assembly of the present invention on the stethoscope head as is discussed in more detail in connection with FIG.  8 . It will be understood that tab  10  may have other shapes or configurations, such as rounded, so long as such shape or configuration provides sufficient ease of removal and installation while yet providing sufficient hold so that the disposable diaphragm assembly stays in position during use. The configuration shown in FIGS. 4 and 5 is the preferred embodiment of the universal retainer ring of the present invention. Use of the universal retainer ring  8  permits the disposable diaphragm assembly of the present invention to be used with any common or specially designed stethoscopes. 
     The disposable diaphragm assembly of the present invention is comprised of two components, a holding ring and a disposable diaphragm. Both the holding ring and disposable diaphragm are intended to be disposed of and replaced after a single patient use. Referring now to FIGS. 6 and 7, the holding ring  13  is circular in shape having a vertically oriented side portion  14 , the bottom edge of which is molded or attached onto a horizontally oriented lip portion  15 . A disposable diaphragm  20  rests on horizontally oriented lip portion  15 . The interior surface of side portion  14  of holding ring  13  has a radial inwardly protruding tab  17  which is formed by inwardly and downwardly tapered portion  18  and inwardly and upwardly tapered portion  19 . 
     Referring now to FIG. 8, it can be seen that radial inwardly protruding tab  17  interconnects with radial outwardly protruding tab  10  of the universal retainer ring  8  so at hold the disposable diaphragm assembly in place. Referring still to FIG. 8, the disposable diaphragm assembly is shown attached to a stethoscope head  2  having a universal retainer ring  8 . The diameter of outwardly protruding tab  10  of universal retainer ring  8  is slightly larger than the inside diameter formed by side portion  14  of holding ring  13 . Consequently, when the disposable diaphragm assembly is attached to the stethoscope head/universal retainer ring combination, the two tabs  10  and  17  create a snapping type action and connection is made by pushing the stethoscope head  2  and universal retainer ring  8  combination into the holding ring  13 . This also locks and retains the disposable diaphragm  20  in place. By snapping the universal retainer ring  8  and stethoscope head  2  into the holding ring  13 , the disposable diaphragm  20  makes tight contact with the rounded extension  16  on the stethoscope head  2 . This is important for proper sound transmittal. 
     The universal retainer ring  8  may be made from materials such as metal, plastic, or other suitable materials. The holding ring  13  is made from softer, flexible type materials such as, but not limited, to plastics. The difference of the materials and the associated flexible action of the holding ring  13  allows the snapping on and off of the holding ring  13  to the universal retainer ring  8 . 
     The taper portions  11 , 12 ,  18  and  19  allow this on and off snapping action to be possible. The same tapers also assure proper retention of the disposable diaphragm assembly onto the stethoscope head  2 . Furthermore, the taper portions  11 ,  12 ,  18 , and  19  and protruding tabs  10  and  17  assure a tight fit connection of the disposable diaphragm  20  to the stethoscope head  2  and extension  16  which is very important for proper sound transmittal. Once a stethoscope is fitted with a universal retainer ring  8 , disposable diaphragm assemblies may be simply snapped on or off. 
     Certain stethoscope heads, such as the open bell heads used in pediatric practice, as shown in FIG. 9, will not accommodate the universal retainer ring and disposable diaphragm assembly of the present invention. FIG. 9 shows a prior art stethoscope having both a typical stethoscope head  2  and an open bell head  21 . FIG. 9 is partially cross-sectional to show the interior of the open bell head. An alternative disposable protective cover may be used with such open bell heads. Referring now to FIG. 10, a ring type protective cover  22  is shown. Protective cover  22  is in the general shape of a bottle cap, having a solid top surface  23  and a lower ring structure  24 . FIG. 10 shows protective cover  22  in a partially cross sectional view to illustrate the ring structure  24 . Such ring type protective cover  22  may utilize an adhesive means, such as a pressure sensitive adhesive, coated on the inside surface to assure retention of the protective cover  22  on the open bell head  21  during use. Alternatively, protective cover  22  may be made of some flexible material, such as a resilient plastic, and sized to fit snugly over the open bell head  21 . Other suitable materials, include but are not limited to, rubber and paper. Protective cover  22  may be made in its entirety from the same material or in the alternative may be made from a plurality of materials. For example, the top surface could be made of paper attached to a ring structure composed of plastic. 
     It will be understood that the disposable diaphragm assembly of the present invention could also be used with a stethoscope having a head designed in the shape of the universal retainer ring of the present invention. Such a stethoscope head  28  is shown in FIG.  11 . The dimensions and shape of radial outwardly protruding tab  25  are identical to the dimensions and shape of the radial outwardly protruding tab  10  of the universal retainer ring  8 . Similarly, tapered portions  26  and  27  are of the same size and shape as tapered portions  11  and  12 , respectively, of universal retainer ring  8 . Thus, the disposable diaphragm assembly of the present invention could be used with stethoscope head  28 . 
     In a similar manner, an open bell head could be specifically constructed to better hold a protective cover. Referring now to FIG. 12, a combination standard head and open bell head stethoscope is shown in which the standard head is shaped in the form of the universal retainer ring of the present invention, as discussed above in connection with FIG.  11 . Open bell head  29  us formed with a outwardly protruding lip  30 . A protective cover  31  attaches by means of snapping on to the open bell head  29  by interlocking an internal indentation  32  with lip  30 . Protective cover  31  is made from a flexible material, such as plastic or rubber, allowing easy attachment and removal. 
     FIG. 13 shows a portable, disposable dispenser  33  for the disposable diaphragm assembly of the present invention. Dispenser  33  may be made from paper, card-board, plastic or other suitable materials and is designed to, hold a number of disposable diaphragm assemblies within its interior. The dispenser  33  is tubular in shape and sized to snugly hold the disposable diaphragm assembly of the present invention within the dispenser&#39;s interior diameter. Dispenser  33  is designed with perforations  34  and  35  and a removable, peel-off-type top  36 . Dispenser  33  is further comprised of a bottom portion means for preventing the disposable diaphragm assemblies from falling out the bottom of the dispenser  33 . Such means may include, without limitation, a cross-member extending across the bottom diameter or a flat integral bottom face. Perforations  35  run along the circumference of the dispenser  33  and are vertically spaced at intervals approximately equal to the height of a single disposable diaphragm assembly. Scored rings  37  are formed by perforations  35 , the number of rings equaling the number of disposable diaphragm assemblies held within the dispenser  33 . Perforations  34  run vertically across each scored ring  37  with the position of perforations  34  staggered in adjacent scored rings. 
     FIG. 14 is a partial cross-sectioned view of the dispenser  33  illustrating the stacking of disposable diaphragm assemblies  38  within the dispenser  33 . Once the top  36  is removed, a stethoscope head  2  with the universal retainer ring  8  is inserted at an angle into the dispenser  33  to attach a disposable diaphragm assembly  38  to the retainer ring  8 . As the stethoscope head/retainer ring is pressed down to snap into the disposable diaphragm assembly  38 , holding ring  13  of the disposable diaphragm assembly  38  flexes outwardly causing scored ring  37  to fully or partially break open at its perforation  34 , as shown in FIG.  15 . After the disposable diaphragm assembly  38  is attached to the universal retainer ring  8 , the broken scored ring  37  may be removed by peeling it off along the perforation  35 . 
     Because the disposable stethoscope diaphragm assemblies  38  are stacked in the interior of the dispenser  33  with the interior, non-patient face of the disposable diaphragm  20  facing up, the patient side of the diaphragm  20  and the outer portion of lip portion  15  of holding ring  13 , both of which come into contact with the patient are always clean prior to use. 
     FIG. 16 displays an alternative embodiment of a dispenser  33  in which each scored ring  37  is further comprised of an outwardly projecting pull tab  39  used to remove a broken scored ring  37  from the dispenser  33 . 
     A stationary dispenser  70  is illustrated in FIGS. 17-20. The stationary dispenser is comprised of three platforms, shown as  40 ,  41 , and  42 . Platform  40  is the base platform and has a raised projection at its center called the pivot point  43 . Pivot pin  43  protrudes upward into a recess in the bottom surface of platform  41 . This allows platform  41  to rotate on top of platform  40 . The outside diameter of platform  41  has a wavy configuration. This wavy configuration allows easy rotation by hand of platform  41 . It will be understood that motorized rotation may also be accomplished by actuating a motor and associated switches and timers. Such motorized methods and related devices are commercially available and may be incorporated into the present invention by one of skill in the art. Platform  41  has four circular recessed areas  46 ,  63 ,  64  and  65 , the interior diameter and depth of which are slightly larger than the outside diameter of the disposable diaphragm assembly  38 . 
     Platform  42  is three-quarters circular in shape and sits above platform  41  without interfering with the rotation of platform  41 . Platform  42  is connected to platform  40  through a horizontal lip  49  which protrudes downward around platform  41 . Lip  49  contains a projection  50  which snaps into an indentation  51  on platform  40 . That is, platform  41  is rotatably sandwiched between platforms  40  and  42 . Because platform  42  is not completely circular, a section of platform  41  and the recess  46  in platform  41  is exposed. 
     Stationary dispenser  70  is further comprised of three tubular containers,  53 ,  54 , and  55 , extending upward from platform  42 . Platform  42  is further comprised of three tubular receptacles  56 ,  57  and  58 , which extend upwardly from the top surface of platform  42  and which are equally spaced at 90 degrees from each other. Tubular receptacles  56 ,  57  and  58  are sized such that tubular containers  53 ,  54 , and  55  can be inserted and contained securely within the receptacles. 
     Each of tubular container  53 ,  54  and  55  hold a number of disposable diaphragm assemblies. The number of disposable diaphragm assemblies which each tubular container can accommodate depends upon the length of the containers. A tubular container of eight inches in height will hold about thirty-two disposable diaphragm assemblies. It will be understood that in an alternative embodiment, tubular containers  53 ,  54  and  55  may be unitarily molded as a part of and extending upwardly from platform  42 . 
     Platform  40  is further comprised of a detente pin  47  and a spring  48 . The detente pin  47  mates one of four recesses  43  in platform  41 . The four recesses  43  are placed 90 degrees apart on the bottom surface of platform  41  and are located to assure proper location of the containers  53 ,  54  and  55  over the recessed areas  63 ,  64  and  65 . The three tubular containers  53 ,  54  and  55  are filled with disposable diaphragm assemblies and sit on top of platform  42  over the recessed areas  63 ,  64  and  65 . Thus the recesses  63 ,  64  and  65  accept the lowermost disposable diaphragm assemblies in each of containers  53 ,  54  and  55 , respectively. As the platform  41  is rotated from détente recess to the next detente recess  43 , a disposable diaphragm assembly is exposed. In this position of platform  41  with a disposable diaphragm assembly inside the recess  46 , a stethoscope prepared with the universal retainer ring  8  or configured as described in connection with FIG. 11 or  12  may be inserted in recess  46  and the disposable diaphragm assembly  38  may be attached to the stethoscope. 
     Disposable diaphragm assemblies are stacked within containers  53 ,  54  and  55  such that the interior portions of the disposable diaphragm assemblies are facing up. Thus, those surfaces which come into contact with a patient are kept clean until used. 
     The rotational process of platform  41  is repeated to locate the next disposable diaphragm assembly in recess  46  of the platform  41 . The rotation of platform  41  may be repeated until all containers  53 ,  54  and  55  are empty. 
     In an alternative embodiment of the stationary dispenser of the present invention, an openable cover  61  (not shown) in the size and shape to cover the exposed recess  46  may be added to platform  42 . Cover  61  would protect any unused disposable diaphragm assembly within recess  46  until needed. When in use, cover  61  would be opened to expose recess  46  and a new disposable diaphragm assembly so that the assembly could be attached to a stethoscope. 
     It will be understood that a number of configurations for dispensers, both stationary and portable/disposable, are possible. In the present invention, the critical element for such dispensers is the ability to load a disposable diaphragm assembly without contaminating the assembly with the hands of medical personal. The dispensers of the present invention accomplish this goal by maintaining the cleanliness of the assemblies while the assemblies are stored in the dispenser and while the assemblies are loaded onto stethoscopes. 
     While a limited number of the embodiments of the present invention have been discussed herein, it will be understood that the invention is-not limited but rather that various alterations could be made on the present invention without departing from the scope of the invention.