An ergonometric chestpiece for a stethoscope adapted to receive auscultatory sounds from a body and adapted to be coupled to an earpiece for a user. The chestpiece is adapted to be grasped by a thumb and at least one finger of the user. The chestpiece has a bottom surface which is generally planar and is adapted to be placed near the body for receiving the auscultatory sounds. The chestpiece has an upper portion opposite the bottom surface. The upper portion has a raised center portion defining left and right gripping surfaces which form recesses defined by the left and right gripping surfaces and by a surface generally parallel to but opposite the bottom surface. The left and right gripping surfaces are adapted to receive the thumb and the at least one finger of the user. Left and right gripping surfaces along with the surface generally parallel to but opposite the bottom surface forms a physical stop for the thumb and the at least one finger from contacting the body when the thumb and the at least one finger grasp the raised center of the upper portion. The gripping surfaces may be defined by left and right walls disposed generally normal to the bottom surface. The left and right walls may be concave. The ergonometric chestpiece may be generally circular and the left and right walls are cylindrically concave around axes generally orthogonal to the bottom surface. The top surface of the raised center portion may be sloped with respect to the bottom surface, the top surface being closer to the bottom surface at the front of the chestpiece than at the rear of the chestpiece.

BACKGROUND OF THE INVENTION 
The present invention relates generally to stethoscopes and, more 
particularly, to chestpieces for stethoscopes, especially electronic 
stethoscopes having operational controls located on the chestpiece. 
Stethoscopes have long been used by physicians to monitor auscultatory 
sounds. Typically stethoscopes have been comprised of a head or 
chestpiece, a sound transmission mechanism and an earpiece assembly. The 
chestpiece is adapted to be placed against the skin of a patient for 
gathering the auscultatory sounds. The sound transmission mechanism 
transmits the gathered sound to the earpiece where the physician may 
monitor the sound. 
The chestpiece of conventional auditory stethoscopes are usually quite 
simple physically. They are usually round disk shapes sometimes dual 
sided, top and bottom, to allow either side of the chestpiece to contact 
the skin of the patient, perhaps for the gathering of auscultatory sounds 
in different frequency ranges. 
U.S. Pat. No. 4,071,694, Pfeiffer, Stethoscope, (assigned to the assignee 
of the present invention) describes a stethoscope which has both an 
electronic and an acoustic capability. The chestpiece of the stethoscope 
described in the Pfeiffer patent has a conventional shape and achieves a 
conventional function. The chestpiece is round and generally flat making 
the stethoscope appear and handle similarly, and has ergonometrics similar 
to, conventional stethoscopes. 
Recently, the auditory sound gathering, transmission and delivery functions 
of stethoscopes have been supplemented or supplanted by electronic 
gathering or transmission. 
The incorporation of electronic circuitry into the stethoscope has been a 
considerable design problem for the engineer. Typically, the electronic 
circuitry increases the physical size of the stethoscope package. Either 
the size of the chestpiece is increased in size dramatically or an 
additional enclosure to house the electronics is located between the 
chestpiece and earpiece assembly or both. In both of these cases, the 
resulting stethoscope is bulky, cumbersome to use and not easily storable 
between uses. The result, thus, is a stethoscope which is distinctly not 
ergonometric. 
The problem of making a stethoscope, especially an electronic stethoscope 
ergonometric can be seen by reference to U.S. Pat. No. 3,790,712, Andries, 
Electronic Stethoscope System. The Andries patent describes an electronic 
stethoscope which has a chestpiece sized and shaped like a large 
rectangular, cumbersome box. This large, cumbersome box houses the 
electronic circuitry of the stethoscope. The box has a projecting member 
15 with a forward lip portion 16 for engagement with a skin surface. This 
projecting member 15 has a conically shaped interior wall with a centrally 
located sound opening 18. 
The stethoscope described in U.S. Pat. No. 4,170,717, Walshe, Electronic 
Stethoscope, has a chestpiece having an elongated housing 20 carrying a 
body piece 21 which includes an annular ring 21a to be placed against a 
patient's body. A thin diaphragm 22 extends across the opening formed by 
ring 21a and is acoustically coupled to a microphone 23. Again, the 
chestpiece of the stethoscope described in Walshe '717 is large, bulky and 
has a generally elongated rectangular shape rounded on one end. 
The chestpiece 120 of the stethoscope described in U.S. Pat. No. 4,254,302, 
Walshe, Electronic Stethoscope, has an annular upper portion 160, a 
relatively larger annular lower portion 161 and a reduced diameter 
immediate control portion 162 adapted to be interdigitally grasped, 
particularly with the doctor's first and second fingers. The controls of 
the electronic stethoscope are positioned on the reduced diameter 
immediate control portion 162 for protection. 
The stethoscope described in U.S. Pat. No. 4,723,555, Shue, 
Multi-Functional Radio/Wire Stethoscope Apparatus, and U.S. Pat. No. 
4,878,501, Shue, Multi-Functional Radio/Wire Stethoscope Apparatus, has a 
chestpiece with a diaphragm on one side and a bell on the other designed 
for gathering auscultatory sounds. The chestpiece generally is shaped to 
have a truncated cone on each side with the open end of the cone adapted 
for contacting the patient's skin. The truncated section of the cones are 
coupled together with a cylinder forming a circular portion with a smaller 
diameter than the open end of the cones. 
U.S. Pat. No. 4,440,258, Packard, Tunable Stethoscope, (assigned to the 
assignee of the present invention) describes a stethoscope with a 
chestpiece (stethoscope head) having a body member having a first 
generally bell-shaped recess, a diaphragm, a suspension member for 
connecting the diaphragm to the body member, and an immobilizing means 
located within the first recess. The suspension member affords movement of 
the diaphragm in a direction generally perpendicular to the plane of the 
diaphragm without the shape of or lateral tension in the diaphragm 
changing substantially. The movement of the diaphragm allows the 
stethoscope to be tunable with respect to auscultatory sounds. 
The chestpiece of the stethoscope described in the Packard patent has a 
body member 11 formed of conventional material. The body member 11 has a 
substantially disk like portion 18 and a column 19 emanating therefrom. 
The top 20 of column 19 is substantially flat. Front section 21 of column 
19 is sloped away from top 20, is concave in configuration and is curved 
to meet the top surface of disk like portion 18. Side sections 22 and 23 
and back section 24 are arcuate in configuration. The shape of body member 
11 permits the physician to grasp column 19 from the top with the index 
finger being placed on front section 21 and each of the thumb and the 
middle finger adjacent disk 18 on opposite sides of column 19 with a 
fitting 15 passing between those fingers. 
The column 19 of the chestpiece of the stethoscope described in the Packard 
patent allows the chestpiece to be easily grasped by the physician. The 
column 19 is generally cylindrical with concave side walls. The 
cylindrical shape of column 19 limits the precise positioning and indexing 
of the fingers and space for positioning controls and indicators. 
SUMMARY OF THE INVENTION 
The chestpiece of the present invention is easily grasped by the physician 
and fits comfortably into the physician's hands. The top surface of the 
base member prevents the physician's fingers from directly contacting the 
patient's skin while affording ample holding and grasping capacity. The 
raised center portion has a physical stop which prevents the fingers of 
the physician from sliding with respect to the chestpiece and, perhaps 
sliding off of the chestpiece. In a preferred embodiment of the invention, 
the physical stop in the chestpiece is provided by substantially vertical 
concave side walls formed by gripping surfaces which flare out and prevent 
the forward or backward slide of the fingers of the physician. 
The raised center portion of the chestpiece slopes downward toward the 
front of the chestpiece allowing the chestpiece to comfortably be nested 
into the palm of the hand of the physician. 
With the sloped top of the raised center portion of the stethoscope 
chestpiece fits into the palm of the physician's hand and the physician's 
fingers comfortably holding the side walls and being prevented from 
slipping forward, having a finger available to operate one or more 
operational controls. These controls may be located, preferably in a 
recessed fashion, on top of the forward portion of the raised center 
portion. 
Thus, in one embodiment the present invention provides an ergonometric 
chestpiece for a stethoscope adapted to receive auscultatory sounds from a 
body and adapted to be coupled to an earpiece assembly, or binaural 
assembly, for a user. The chestpiece is adapted to be grasped by a thumb 
and at least one finger of the user. The chestpiece has a bottom surface 
which is generally planar and is adapted to be placed near or in 
comfortable contact with the body for receiving the auscultatory sounds. 
The chestpiece has an upper portion opposite the bottom surface. The upper 
portion has a raised center portion defining left and right gripping 
surfaces which form recesses defined by the left and right gripping 
surfaces and by a surface generally parallel to but opposite the bottom 
surface. The left and right gripping surfaces are adapted to receive the 
thumb and the at least one finger of the user, respectively. The raised 
center portion form a physical stop for the thumb and the at least one 
finger from contacting the body when the thumb and the at least one finger 
grasp the raised center of the upper portion. 
In a preferred embodiment, the gripping surfaces are defined by left and 
right walls disposed generally normal to the bottom surface. In a 
preferred embodiment, the left and right walls are concave. In a preferred 
embodiment, the ergonometric chestpiece is generally circular and the left 
and right walls are cylindrically concave around axes generally orthogonal 
to the bottom surface. In a preferred embodiment, the top surface of the 
raised center portion is sloped with respect to the bottom surface, the 
top surface being closer to the bottom surface at the front of the 
chestpiece than at the rear of the chestpiece. 
In a preferred embodiment, the ergonometric chestpiece further has at least 
one operational control placed on the raised center portion in a position 
easily manipulated by a finger of the user. In a preferred embodiment, at 
least one operational control is mounted on the top surface of the raised 
center portion of the chestpiece. In a preferred embodiment, at least one 
control is placed on the forward portion of the raised center portion of 
the chestpiece. In a preferred embodiment, the chestpiece has a plurality 
of controls all located on the forward portion of the top surface of the 
raised center portion, the plurality of controls all being positioned for 
manipulation by a finger of the user. In a preferred embodiment, each of 
the plurality of controls is recessed to prevent inadvertent actuation of 
a control function.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The stethoscope 10 illustrated in FIG. 1 consists of a chestpiece 12, or 
stethoscope head, a binaural assembly 14 and a connecting tube 16. The 
binaural assembly 14 has two earpieces 18 and 20 adapted to fit in or near 
the ear of a user, typically a physician or other medical professional. 
Tubes 22 and 24, generally acoustic tubes, couple earpieces 18 and 20, 
respectively to connecting tube 16 which in turn is coupled to chestpiece 
12. 
The sound transmission system of stethoscope 10 may be entirely acoustic as 
is well known in the art. However, it is also contemplated that the sound 
transmission system of stethoscope 10 could also be electronic. In this 
situation, an acoustic to electronic transducer, a microphone 42, would be 
located along the acoustic sound transmission path, typically in or very 
near the chestpiece 12, and even more typically in the chestpiece 12 
positioned near the bottom surface 36, shown in FIG. 5, of the chestpiece 
12 so as to be near the source of auscultatory sounds. Electronic means 
would then typically amplify, or otherwise process, the electrical signal. 
The electrical signal may be transmitted electrically to an electrical to 
acoustic transducer, a speaker, typically located nearer the earpieces 22 
and 24 of the stethoscope 10 or to an external signal processing device. 
Of course, a stethoscope of a combination acoustic and electronic, or dual 
acoustic and electronic, is also contemplated. 
In the preferred embodiment, stethoscope 10 is of dual acoustic and 
electronic construction. An acoustic path exists from chestpiece 12, along 
connecting tube 16 through tubes 22 and 24 to earpieces 18 and 20 of 
binaural assembly 14. In addition, a microphone is positioned within 
chestpiece 12. The electrical signal obtained from the microphone is 
amplified and processed by conventional electronic circuitry located 
within chestpiece 12. Electrical wires transmit the processed electrical 
signal within and along connecting tube 16. A speaker is located at 
juncture of tube 22 and 24 and connecting tube 16. This speaker transforms 
the auscultatory sounds back to the acoustic domain where tubes 22 and 24 
transmit the acoustic sounds to earpieces 18 and 20. 
The top surface of chestpiece 12 is visible in FIGS. 1, 2 and 3 The bottom 
surface 36 of the chestpiece 12 is adapted to be placed near the source of 
auscultatory sound, or, in a preferred embodiment, comfortable contact the 
skin of the patient. Chestpiece 12 has a raised center portion 26 which is 
adapted to be grasped by the thumb and one of the fingers of the user, 
typically the thumb and middle finger. Left and right gripping surfaces 28 
and 30 of the raised center portion 26 are adapted to engage the gripping 
appendages (thumb and finger) of the user. Gripping surfaces 28 and 30 are 
defined by walls which are concave generally along one or more axis 
generally orthogonal to the bottom surface of chestpiece 12 and further 
are defined by the surface 32 of the chestpiece 12 opposite the bottom 
surface. In a preferred embodiment, the walls defining gripping surfaces 
28 and 30 are generally vertical. The area formed by the walls of gripping 
surfaces 28 and 30 and, preferably planar, surface 32 define left and 
right recesses which are adapted to receive the thumb and at least one 
finger of the user. These gripping surfaces 28 and 30 are preferably 
formed by concave cylindrical surfaces which flare outward toward the 
front, and preferably toward the rear, of the chestpiece 12. 
The left and right recesses formed into raised center portion 26 allow 
gripping surfaces 28 and 30 to act as a physical stop which prevents the 
fingers or thumb of the user from sliding forward during use and 
eliminates the possibility of the the fingers and/or thumb slipping off of 
the chestpiece 12. This slippage could result in an interruption of the 
monitoring of auscultatory sounds and further could result in pain, 
embarrassment or lack of confidence to the user and/or the patient. The 
flaring of the concave shape of the gripping surfaces to an angle outward 
of directly forward in the chestpiece facilitates the physical stop. It is 
preferred that this angle be at least thirty degrees from straight forward 
and, still further preferably, this should be at least about forty-five 
degrees but, for comfort, substantially less than ninety degrees from 
straight forward on the chestpiece 12. 
It is preferred that the ergonometric chestpiece 12 has a shape which is 
generally circular. Further, where the shape of chestpiece 12 is generally 
circular, the left and right walls formed by gripping surfaces 28 and 30 
are preferred to be cylindrically concave around axes generally orthogonal 
to the bottom surface. 
One or more operational controls, in this embodiment a rocker switch 34, is 
positioned on the top surface of the raised center portion 26. Rocker 
switch 34 is positioned roughly in the middle of raised center portion 26 
generally forward of gripping surfaces 28 and 30. In this position, rocker 
switch 34 is easily available to be manipulated by the index finger of the 
user when gripping surfaces 28 and 30 are grasped by the user's thumb and 
middle finger. Typical uses of rocker switch 34 are to turn power to the 
stethoscope 10 on, or off, when the rocker switch 34 is rocked in a first 
direction, or a second direction, or similarly to increase, or decrease 
the volume of the auscultatory sound delivered to the user or control 
other functions as appropriate. 
Detailed side, front and rear views of chestpiece 12 are illustrated in 
FIGS. 2, 3 and 4, respectively. Bottom surface 36, which is preferably 
generally planar, is adapted to be placed near the source of auscultatory 
sound, and preferably, adapted to be placed on the skin of the patient. 
Surface 32, helping to define the gripping recesses, is preferably also 
generally planar and parallel to the plane formed by bottom surface 36. As 
could be seen with respect to FIG. 1, chestpiece 12 has a raised center 
portion 26 into which gripping surfaces 28 and 30 are defined by walls. 
Again, the walls forming the gripping surfaces 28 and 30 flare to form a 
physical forward stop for the user's fingers. 
The top surface of raised center portion 26 preferably is sloped downward 
from rear to front of chestpiece 12 to form a surface which may be easily 
held in the palm of the hand of the user and allow easy positioning under 
a garment or a medical drape. Thus, raised center portion 26 is higher, 
i.e., thicker, at the rear of the chestpiece 12 than at the front of the 
chestpiece 12. 
Connecting tube 16 shown in FIG. 5 is coupled to chestpiece 12 at the rear 
of chestpiece 12 at opening 38 at an angle 60 positioning connecting tube 
16 to minimize interference with the user and to not cause discomfort to 
the patient. 
FIGS. 5 and 6 illustrate a side cross-sectional view and a side explosion 
view of a preferred embodiment of chestpiece 12. Bottom surface 36 is 
illustrated as being generally planar. A diaphragm 40 is held in place by 
diaphragm retainer 41 and is stretched across an opening in the bottom 
surface 36 which allows for the entry of auscultation sounds into the 
chestpiece 12. A microphone 42 is mounted by microphone holder 43 within 
chestpiece 12 and is positioned in close proximity to diaphragm 40. An 
acoustic passage 44 allows for the simultaneous transmission of acoustic 
signals. Rocker switch 34 is mounted on the forward part of raised center 
portion 26. Rocker switch 34 activates silicon rubber keypad with 
conductive rubber pads 46. When rocker switch 34 is pressed the conductive 
rubber pads 46 provide the switching or control function bridging 
conductive elements on printed circuit board 50. An O-ring 51 helps to 
seal the chestpiece 12 from ingress of contaminants. 
FIGS. 7, 8, 9 and 10 illustrate an alternative embodiment of the chestpiece 
12 of the present invention. As in the first embodiment, chestpiece 12 has 
a planar bottom surface 36, a raised center portion 26 which slopes 
downward toward the front and gripping surfaces 28 and 30. The embodiment 
of chestpiece 12 illustrated in these Figures differs with respect to the 
number, placement and form of the operational controls. It is preferred 
that the shape and separation of the operational controls be chosen for 
ease of identification by sight from the top of the chestpiece 12 and/or 
feel, in order to provide ease of operation and minimum erroneous or 
inadvertent operation. 
A slide switch 52 is located in recess 54 on the top surface and in the 
forward portion of raised center portion 26. Push button switch 56 is also 
located within recess 54. Recess 54 itself is arcuate, skewing toward the 
outside edge of raised center portion 26 similar to the wall formed by 
gripping surface 28. Further, a rotary control 58, in a preferred 
embodiment a potentiometer, is positioned in a recess near the front edge 
of raised center portion 26 and chestpiece 12. The rotary action of 
control 58 is in a plane parallel to the plane of bottom surface 36. In a 
typical function, slide switch 52 may be used to control to function or 
mode of operation, such as the frequency response, of stethoscope 10, push 
button switch 56 may be used to control the power to the stethoscope 10 
and rotary switch 58 may be used to control the volume of the stethoscope 
10. The presence of power to stethoscope 10 is indicated by light emitting 
diode 62. All of these controls are easily accessible to and easily 
manipulated by the index finger of the user. Preferably, all of the 
controls and indicators can be read from the top of the chestpiece 12. 
Another alternative embodiment of chestpiece 12 is illustrated in FIGS. 11, 
12, and 13. As in the first two embodiments, chestpiece 12 has a planar 
bottom surface 36, a raised center portion 26 which slopes downward toward 
the front and gripping surfaces 28 and 30 defining recesses with the 
assistance of surface 32. The embodiment of chestpiece 12 illustrated in 
these Figures differs with respect to the number, placement and form of 
the operational controls and indicators. 
In this embodiment, first and second push button switches 60 and 62 are 
located on the top surface and in the forward portion of raised center 
portion 26. Push button switch 60 may be used to control a first function 
or mode of operation, such as the frequency response, of stethoscope 10. 
Push button switch 62 may be used to control a second function or mode of 
operation, such as the power to the stethoscope 10. All of these controls 
are easily accessible to and easily manipulated by the index finger of the 
user. 
Thus, chestpiece 12 functions quite ergonometrically in use by the 
physician or other health care professional. 
The chestpiece 12 is easily grasped by the physician and fits comfortably 
into the physician's hands. The surface 32 on the base of the chestpiece 
12 opposite from bottom surface 36 (as shown in FIG. 2) prevents the 
physician's fingers from directly contacting the patient's skin while 
affording ample holding and grasping capacity for manipulation of the 
chestpiece 12. The raised center portion 26 has a physical stop which 
prevents the fingers of the physician from sliding with respect to the 
chestpiece 12 and, perhaps sliding off of the chestpiece 12. The physical 
stop in the chestpiece 12 is provided by substantially vertical concave 
side walls which flare out toward the front, and preferably toward the 
rear, and prevent the forward or rearward slide of the fingers of the 
physician. 
The raised center portion 26 of the chestpiece 12 slopes downward toward 
the front of the chestpiece 12 allowing the chestpiece 12 to be held 
comfortably in the palm of the hand of the physician and be easily 
positioned under a garment or medical drape. 
With the sloped top of the raised center portion 26 of the stethoscope 
chestpiece 12 being held in the palm of the physician's hand and the 
physician's fingers comfortably holding the gripping surfaces 28 and 30 
and being prevented from slipping forward, a finger is available to 
operate one or more operational controls. These controls may be located, 
preferably in a recessed fashion, on top of the forward portion of the 
raised center portion 26. 
Thus, it can be seen that there has been shown and described a novel 
ergonometric stethoscope chestpiece. It is to be recognized and 
understood, however, that various changes, modifications and substitutions 
in the form and the details of the present invention may be made by those 
skilled in the art without departing from the scope of the invention as 
defined by the following claims.