US 3633703 A
A stethoscope head made entirely of inexpensive plastic adapted for manufacture as a low-cost item having a diaphragm permanently sealed at its periphery to the diaphragm of a shell. The stethoscope head is provided with an arcuately curved diaphragm adapted to conform to the body or arm of a human with tabs extending therefrom for attachment of straps whereby the stethoscope may be attached to the body.
Description (OCR text may contain errors)
United States Patent inventor David Littmann Needham, Mass.
Appl. No. 93,108
Filed Nov. 27, 1970 Patented Jan. 11, 1972 Assignee Minnesota Mining 8: Manufacturing Co.
Maplewood, Minn. Continuation-impart of application Ser. No. 663,423, Aug. 25, 1967, now Patent No. 3,543,875. This application Nov. 27, 1970, Ser. No. 93,108
MOTORING DEVICES 9 Claims, 6 Drawing Figs.
U.S. Cl 181/24,
128/205 S Int. Cl A611) 7/02 Field of Search 181/24, 32
R; l28/2.05 S, 2.05 C
[5 6] References Cited UNITED STATES PATENTS 1,445,711 2/1923 Rayder 181/24 3,095,941 7/1963 Hassan..... 181/32 3,144,091 8/1964 Bodenger 181/24 3,416,516 12/1968 Cohen et al 128/205 S Primary Examiner-Stephen J. Tomsky Attorney-Wolf, Greenfield & Sacks ABSTRACT: A stethoscope head made entirely of inexpensive plastic adapted for manufacture as a low-cost item having a diaphragm permanently sealed at its periphery to the diaphragm of a shell. The stethoscope head. is provided with an arcuately curved diaphragm adapted to conform to the body or arm of a human with tabs extending therefrom for attachment of straps whereby the stethoscope may be attached to the body.
PAIENIEUJAI 1 1 m2 3. 633 703 SHEET 2 BF 2 FIG. 4
MOTORING DEVICES This application is a continuation-in-part of US. Pat. application Ser. No. 663,423 filed Aug. 25, I967 now US. Pat. No. 3,543,875.
BACKGROUND OF THE INVENTION This invention relates to a stethoscope head adapted for use as a monitoring device'for blood pressure and other monitoring purposes.
In the stethoscope art which has heretofore developed, stethoscope construction has been of highly specialized and relatively expensive manufacture and, additionally, it is extremely limited in use. The stethoscopes which are commonly available are primarily made of steel, aluminum or other metals, with separable diaphragms secured to the metal portions by a ring or other similar mechanisms. These stethoscopes consequently are made of a number of different compounds carefully machined or shaped and fitted together. Such stethoscope heads ordinarily sell for no less than several dollars even at wholesale and therefore cannot be adapted for disposal after a single use. Further, the stethoscopes heretofore available are not designed for use as a constant monitoring device for constantly reading blood pressure or other body functions.
SUMMARY OF THE INVENTION It is an object of the present invention to overcome the foregoing limitations and other limitations of the prior art. In the present invention a simple and inexpensive stethoscope head, formed entirely of plastic, is capable of being injected molded or vacuum formed and because of its being injection molded or vacuum formed and because of its inexpensive construction can be disposed of after a single use. The invention provides a stethoscope head which is formed with a flexible diaphragm, arcuate in cross section in at least one plane and which is adapted to hug the contour of a patients arm or chest. The stethoscope head is designed to be secured in such position by an integral strap or other means for constant monitoring purposes. Further object of the invention is to provide an improved stethoscope headpiece having a curved diagram that is adapted to conform closely to a patients body or arm and thereby provide more intimate contact over a larger surface than has heretofore been possible with currently available Stethoscopes. A further object of the invention is to provide a stethoscope headpiece having a diaphragm which is sealed on bonded completely to the shell or casing of the headpiece to provide an improved air chamber that is not likely to leak and thereby will not affect adversely the sound generated within and transmitted through the chamber. Still another object of the invention is to provide an improved diaphragm of rectangular configuration having an arcuate surface that is more comfortable to a patient.
The instant invention employs a stethoscope chest piece or headpiece formed entirely of plastic, preferably molded, and consisting of a plastic shell having a periphery with an outwardly extending flange to which is sealed or bonded a diaphragm, also preferably formed of plastic. The diaphragm is arcuately shaped in one plane intersecting the diaphragm. In the preferred embodiment the diaphragm is rectangular in shape and the shell is provided with tabs adapted to be secured to a blood pressure cufi or strap for attachments to a patients arm or body for monitoring purposes.
BRIEF DESCRIPTION OF THE DRAWINGS The foregoing objects and advantages of the present invention will be understood more fully when considered in conjunction with the accompanying drawings in which:
FIG. 1 is a top plan view of a stethoscope head embodying a preferred form of the invention;
FIG. 2 is a fragmentary cross sectional view of the embodiment shown in FIG. 1 taken partially along the line 2-2 of FIG. 1;
FIG. 3 is a cross-sectional view taken along the line 3-3 of FIG. 2;
FIG. 4 is a top plan view of a modified stethoscope head of the type shown in FIGS. 1, 3;
FIGS. 5 is a fragmentary cross-sectional view of the embodiment shown in FIG. 4 taken partially along the line 5--5 of FIG. 4; and
FIG. 6 is a cross-sectional view taken along the line 6-6 of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the embodiments illustrated in FIGS. 1-3, there is shown a stethoscope head particularly adapted for use in connection with constant monitoring of body functions. The stethoscope head is designed to be attached to a blood pressure cuff for direct attachment to patients arm or chest. The construction illustrated in FIGS. I-3 is fabricated preferably of an injection molded or vacuum formed plastic such as polystyrene, polypropylene or the like. The head is formed with a diaphragm 10, preferably of very thin material which may, for example, be of the order of magnitude of 0.008 inch thick. This diaphragm is generally rectangularly in shape but may be provided with rounded corners. The diaphragm is arcuately bent with the radius of the are being of the order of magnitude of approximately I.5 inches to 4 inches, depending on its application.
The periphery of the diaphragm is bonded or otherwise approximately secured along a margin 11 about its entire periphery to a casing or shell 12. The shell 12 may be vacuum formed or molded as desired and is provided with an arcuate inner surface 13 and an arcuate outer surface 14. These surfaces may, if desired, be tapered from a thicker portion near the center of the shell, as in 15, to a thinner portion at the periphery of the shell indicated at 16. The taper may, for example, include a thickness of 0.060 inch at 15 and 0.040 inch at 16. This shell, therefore, is much thicker and more substantial than the thickness of the diaphragm. The shell 12 is bonded or otherwise sealed to the entire periphery 11 of the diaphragm 10. The bond or seal may be effected by any suitable means much as for example, heat sealing or an appropriate adhesive. The center of the shell is provided with a boss or projection 20, which is integrally formed with the shell 12, has an opening 25 which is coaxial with the axis of the diaphragm 10. The opening 25 is continuous with the opening 26 at right angles thereto which is formed by a tubular extension 27 also integral with the head 20. The extension 27 may be provided with a series of outwardly extending ridges 28 or grooves.
A pair of tabs 30, 31 are formed integrally with the shell 12 at opposite sides thereof and also may be arcuate in shape as viewed in a plane taken longitudinally through the stethoscope head. The tabs, 30, 31 preferably are somewhat thinner than the thinest portion of the shell but are thicker than the diaphragm. Thus, for example, they may be of the order of thickness of 0.03 inch. The tabs 30, 31 are somewhat narrower than the width of the shell and are provided with a series of slots 33 for receiving and securing a strap in a conventional fashion. A pair of cars 34 extend outwardly from the extreme ends of the tabs 30, 31.
The shell 12 is somewhat dome shaped in cross section as illustrated in FIG. 2 and provides a height from the center of the dome shape of magnitude of approximately one-eighth inch. Thus, the stethoscope head has an air volume of irregular shape that is generally rectangular in plan view and which is somewhat crescent shape in vertical cross section.
The stethoscope head is designed for use on patients during operations and at other instances where it is designed to monitor the patients heart beat, blood pressure, or other comparable body function. For example, with this arrangement, the stethoscope is placed over the patients heart and is secured in this position by a strap passing through the slot 33. The opening 26 is connected to a conventional binaural or to another unit of similar purpose by interengaging the tubular extension 27 with a tube of a binaural. The stethoscope also may be secured about the patients arm to monitor his blood pressure in the same general manner. As suggested above, because the unit is made entirely of an inexpensive plastic such as polypropylene and may be vacuum formed or injection molded at relatively low expense, it may be discarded after use during a single operation or bodily function monitoring procedure.
FIGS. 4, 5 and 6 show a modified version of the stethoscope head of FIGS. 1-3. This modification also includes a domeshaped shell 100 and thin diaphragm 102. Straps 104 also are provided with slots 106 for engagement with one attaching strap. in this embodiment, the straps 104 may extend laterally and in a generally straight plane rather than the arcuate configuration of the previous embodiment. The relative thicknesses of the shell 100, diaphragm 102, straps 104 generally are the same as those described in the previous embodiment shown in FIGS. 1-3. in the modified version of the stethoscope head, the outer surface of the shell 100 is reinforced with a series of integrally formed ribs 108 which radiate from a generally central location on the outer surface of the shell 100.
A further feature in the modified stethoscope head relates to the manner in which the tubular member 112 communicates with the acoustical chamber 110 of the stethoscope head. In this modified arrangement, the tube also is molded integrally with the shell but is arranged so that its axial passage 1 14 extends directly from the interior of the dome of the shell in a straight line, rather than in the right-angle configuration shown in the previous embodiment. The integral shell and tube are molded so that the axial passage 114 intersects and opens smoothly into the dome surface of the shell which defines the acoustical chamber 110. The straight line passage thus provided may reduce any acoustical losses or aberration of signals transmitted through the head. Additionally, the straight line passage also permits the overall heightwise dimension of the head to be reduced because the tube 112 need not extend above the outermost and uppermost level of the dome. It should be understood, that the foregoing description of the invention is intended merely to be illustrative thereof and that other embodiments and modifications may be apparent to those skilled in the art without departing from its spirit.
Having thus described the invention what I desire to claim and secure by letters patent is:
1. A stethoscope construction comprising a diaphragm formed of a flat sheet bent into an arcuate shape;
support means for said diaphragm comprising a plastic shell having a continuous portion, means bonding said continuous portion and a continuous portion of said diaphragm together to form an enclosed air mass, said shell having a surface with an arcuate cross section in a plane in which said diaphragm also has an arcuate cross section.
2. A stethoscope construction as set forth in claim 1 wherein said arcuate cross section of said shell has a radius that is no greater than the radius of said diaphragm arcuate cross section.
3. A stethoscope construction as set forth in claim 2 wherein strap engaging tabs extend from said bonded continu ous portions.
4. A stethoscope construction as set forth in claim 3 wherein said tabs extend from opposite ends of said continuous portions and are integrally formed with one of said diaphragm and shell.
5. A stethoscope construction as set forth in claim 4 wherein said tabs are integrally formed with said shell and extend in directions generally continuous with said arcuate cross section.
6. A stethoscope as set forth in claim 5 wherein slots are formed in said tabs.
7. A stethoscope as set forth in claim 6 wherein said shell is formed with an outwardly extending boss having an opening extending therethrough.
8. A stethoscope construction as set forth in claim 7 having a tubular extension continuous with said opening in said boss and integrallyformed with it.
9. A stet oscope construction as set forth in claim 8 wherein said surface of said shell has an arcuate cross section in a plane normal to said first mentioned plane.