Abstract:
This application discloses a stethoscope that utilizes a dual diaphragm construction such that the user of the stethoscope is able to tune in to or to allow the user to select between the isolation and accentuation of either high frequency sounds or low frequency sounds while using a single stethoscope and without the removal of said stethoscope from the patient&#39;s skin.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS  
         [0001]    Not Applicable  
         STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
         [0002]    Not Applicable  
         REFERENCE TO A “MICROFICHE APPENDIX” 
         [0003]    Not Applicable  
         BACKGROUND OF THE INVENTION  
         [0004]    1. Field of the Invention  
           [0005]    This invention relates to the field of medical diagnostic instruments. In particular this invention relates to the field of auscultation, which entails the use of stethoscopes in the diagnosis of patients by medical professionals. Acoustic stethoscopes are one type of stethoscope in the field of medical diagnosis that may be used for the capture of either low or high frequency heart and lung sounds in a patient.  
           [0006]    2. Description of the Related Art  
           [0007]    The prior art discloses a number of different kinds of stethoscopes and variations thereof. Conventional acoustic stethoscopes are disclosed by the prior art that function through sound vibrations colliding with the diaphragm of the stethoscope, and whereas the vibrating or resonating of the diaphragm then causes the reproduction of sound which travels through the acoustic cavity of the stethoscope and to the user&#39;s ears through the stethoscope&#39;s tubing.  
           [0008]    Stethoscopes manufactured with multiple heads that allow a user to accentuate multiple frequency ranges with the same device are well known in the field. One side of such stethoscope is the diaphragm side that is intended for picking up high frequency sounds. Another side may be a bell side that is attuned to reproducing low frequency sounds. Although these multiple sided stethoscopes facilitate a user&#39;s ability to isolate both high and low frequency sounds within the body, the user is required to remove the stethoscope from the patient&#39;s body and then reapply a different side of the stethoscope. This process of switching sides takes time and makes it difficult to find the precise area of the patient&#39;s body that the user had previously placed the stethoscope, and thereby adversely affect the user&#39;s ability to make a quick and accurate diagnosis.  
           [0009]    This invention seeks to introduce a multiple frequency response stethoscope head, which allows a user to accentuate and reproduce low frequency sounds to high frequency sounds without removing the stethoscope head from the patient&#39;s body through utilizing a dual diaphragm stethoscope head construction, which process of changing the frequency response is characterized as “Tuning”.  
         BRIEF SUMMARY OF THE INVENTION  
         [0010]    The preferred embodiment discloses a tunable stethoscope that comprises a single sided stethoscope head whereby the stethoscope can be tuned to different frequencies enabling the pick up of both low frequency sound vibrations and high frequency sound vibrations. The manufacture of stethoscope heads is well disclosed in the prior art and any number of techniques can be used to manufacture the shell of a single sided stethoscope head.  
           [0011]    Pursuant to the preferred embodiments, this application discloses a stethoscope head that permits a user to isolate and reproduce both high and low frequency sound resonating from a patient without removing the stethoscope&#39;s head from its position on the patient&#39;s skin. The preferred embodiment allows the user to select different Tunings for the diaphragm by varying the degree of pressure the user applies to the stethoscope head. According to the preferred embodiment of the present invention, applying the stethoscope head, herein disclosed, to a patient&#39;s skin with minimal contact pressure isolates low frequency resonations, while the stethoscope head remains unresponsive to high frequency resonations. Further, through increased contact pressure between the stethoscope head and the patient&#39;s skin, high frequency sounds are isolated, whereby the disclosed stethoscope remains unresponsive to impact with low frequency resonations.  
           [0012]    The preferred embodiment of this invention discloses a single sided stethoscope head assembly that utilizes two diaphragms of different densities and flexibilities, whereas the combination of the two preceding factors result in the acoustic stiffness of the diaphragm determining the diaphragms frequency response range. The outer diaphragm of this invention is elastomeric with minimal acoustic stiffness exhibiting increased responsiveness and flexibility for accentuating low frequency pickup. The inner diaphragm is denser and semi-rigid in its acoustic stiffness thereby facilitating the pickup of high frequency sounds. The user chooses between the two diaphragms by applying minimal contact pressure between this stethoscope head and the patient&#39;s skin to activate only the exterior diaphragm and through increased contact pressure the user activates the inner diaphragm.  
           [0013]    According to the preferred embodiment of the present invention, the inner diaphragm is such that sound waves pass unobstructed through one or more holes located in the surface of the inner diaphragm, such that the inner diaphragm does not resonate in the disclosed invention&#39;s low frequency mode. Thus, the preferred embodiment allows the low frequency sound waves picked up by the outer diaphragm, in its relaxed state to pass unobstructed through the one or more air holes in the inner diaphragm and travel through to stethoscope&#39;s headset without impacting the high frequency response diaphragm.  
           [0014]    According to another preferred embodiment, the outer elastomeric diaphragm is treated with or comprised of antibiotics or anti-microbial compound in order to promote sterility in the use of the disclosed invention from subject to subject.  
           [0015]    According to another preferred embodiment of the present invention, the outer elastomeric diaphragm can be easily discarded and replaced with a new outer diaphragm, which further promotes the sterility of the disclosed invention through prolonged use of this invention.  
           [0016]    Further the disclosed tunable stethoscope head is universally adaptable to any stethoscope lumen, such that the disclosed invention can be mated to either a single lumen or multiple lumen stethoscope tube.  
           [0017]    According to another embodiment of the present invention, a tunable stethoscope head is incorporated in a standard dual sided acoustic stethoscope with different size heads, which thereby makes this invention suitable for use with both an adult or a pediatric patient. 
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS  
       [0018]    [0018]FIG. 1( a ) shows a side view schematic of the tunable stethoscope head in its relaxed state (Low Frequency Mode).  
         [0019]    [0019]FIG. 1( b ) shows a side view schematic of the tunable diaphragm in its flexed state (High Frequency Mode).  
         [0020]    [0020]FIG. 2( a ) depicts a side view schematic of the tunable stethoscope in its relaxed state as applied to a subject (Low Frequency Mode).  
         [0021]    [0021]FIG. 2( b ) depicts a side view schematic drawing of the tunable stethoscope in its flexed state being applied to a subject (Low Frequency Mode). 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]    In referring to the followings drawings, whereby like reference numbers refer to like parts throughout the various views.  
         [0023]    FIGS.  11 ( a ) and  11 ( b ) show side-view schematics of this tunable stethoscope head, which depict the preferred embodiments of the present invention. The disclosed invention functions through the incorporation of two separate diaphragms, Hard Diaphragm (“HD”)  103  and Elastomeric Diaphragm (“ED”)  106 , having both diaphragms incorporated into a singular housing of a stethoscope head, Shell  101 . Shell  101  has a concave receiving portion that houses the HD  103  and ED  106 , wherefrom the internal mechanics of the disclosed tunable stethoscope permit Tuning to multiple frequency ranges from a single subject.  
         [0024]    Shell  101  has top section, referred to herein as Plate  109 , and which is used as the focal point whereat the user applies pressure to hold the stethoscope against the subject. By the user applying minimal pressure to Plate  109  the user selects the low frequency response mode, or wherefrom the increased application pressure to Plate  109  until ED 106  contacts HD  103  the disclosed invention tunes to high frequency resonations.  
         [0025]    ED  106  is the outer diaphragm, whereby ED  106  is comprised of a chemically inert and durable elastomer, such as Kraton or C-Flex™, and whereas ED  106  is particularly responsive to low frequency sound waves falling between 0 and 250 Hz. ED  106  is approximately parabolic in cross-section with a curled peripheral edge such as to create a lip, whereas the lip forms an opening in ED  106  with a diameter smaller than the diameter of Shell  101 , and which lip is then used as a method of attachment around the exterior rim of Shell  101 . HD  103  is made of a semi-rigid material that allows only for minimal flex that is useful in connection with accentuating high frequency sound modulations over 200 Hz.  
         [0026]    HD  103  is inserted into the open end of Shell  101 , whereby the open end is manufactured as to allow for clearance  105 . HD  103  is held in Clearance  105  through the use of Support Ring  102 , and which support Ring  102  is sized as to have a diameter minimally larger than HD  103  with a minimal width so that Support Ring  102  merely prevents HD  103  from falling out of Shell  101  without affecting HD  103 &#39;s flexibility. Support Ring  102  mates with Groove  110 , which is manufactured into the inner surface of the open end of Shell  101 , such that Support Ring  102  fits securely within Groove  110  and locks into place.  
         [0027]    HD  103  has Air Hole  104 , a circular hole no greater than 1″ in diameter, beneath the opening of Sound Path  108 , and whereby low frequency sound waves generated by ED  106  pass through Air Hole  104 , and thereby, Air Hole  104  prevents their impact with HD  103  preventing HD  103 &#39;s high frequency response. Sound Path  108  is an unobstructed pathway, bored through Shell  101 , which carries sound energy created by the diaphragms to Fixed Barb  107 . Fixed Barb  107  is a hollow elongated member which is used as a means of attaching Shell  101  to tubing of the stethoscope, and whereby said attachment of the tubing to Fixed Barb  107  is accomplished in any suitable manner, such as glue or adhesive, whether known or not yet discovered in the field. Fixed Barb  107  is attached to Shell  101  by physical insertion into Sound Path  108  in Shell  101 , whereas such methods of insertion and attachment are well known in the field.  
         [0028]    [0028]FIG. 1( b ) shows the tunable stethoscope head if operating under its high frequency mode. ED  106  flexes to the point of contact with inner HD  103 , and whereat said point of contact ED  106  and HD  103  act in concert as one diaphragm and further, the joint action increases the acoustic stiffness and enables the accentuation of high frequency sounds in the diaphragms as herein described. Sound created by the vibrations of one or both of the diaphragms is carried through Sound Path  108 , which is bored through Shell  101  and on through Fixed Barb  107 .  
         [0029]    FIGS.  2 ( a ) and  2 ( b ) are depictions of the preferred embodiments of the present invention while being applied to a contact surface, such as the skin of a patient, and being further characterized as the Subject Wall  111 . Pursuant to this invention, when the tunable stethoscope is applied to Subject Wall  111 , resistance is applied to ED  106 , whereby resistance causes ED  106  to flex. When minimal pressure is applied, as shown in FIG. 2( a ), ED  106  does not flex to the point of contact with inner HD  103 . When the disclosed invention is applied to Subject Wall  111 , such as to listen to internal human body sounds through its application to the subject&#39;s skin, low frequency modulations within are picked up by the flexible outer ED  106 . ED  106  responds by transmitting those low frequency modulations to the user through Air Hole  104  in HD  103 , without impacting and activating HD  103  and, thus, HD  103  remains illusory in this stethoscope&#39;s low frequency mode.  
         [0030]    [0030]FIG. 2( b ) shows the disclosed invention being tuned to high frequency sound modulations accomplished through the user increasing the pressure being applied to Plate  109  resulting in additional force being applied to Subject Wall  111 . As a consequence of increasing the pressure, ED  106  and HD  103  are forced together to the point of their contact effectively closing off Air Hole  104 , and therefore when sound waves impact the outer ED  106  the sound waves are impacting HD  103  at the same time. Thus, whereas ED  106  and HD  103  are acting in concert with increased acoustic stiffness, the now operative HD  103  enable the disclosed invention to tune into high frequency resonations.