US1147282A - Stethoscope. - Google Patents

Description

K. M. TURNER.

STETHOSCOPE.

APPLICATION FILED SEPT. 10, 1912.

LMKQSZQ Patented July 20, 1915.

lNVENTOR I BY A M Z:- ATTORNEY h l l l'fi KELLEY M, TURNER, F JAllIAIC-A, NEW YORK, ASSIG-NOE TO GENERALACOUSTIC iv OOMPENY, A CGRPORATION OF NEW,

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Specification of Letters Patent. I Patgntgfl July 2o. 1 Q? Application filed September 10, 1512. Serial 1V0. 719,573.

To all whom it may concern: 7

Be it known that I, K LLEY TURNER, citizen of the United States, and resident of Jamaica, in the county of Queens and 5 State of New York, have invented certain new and usefulImprovements in Stethoscopes, of which the -following is a specification.

This invention relates to Stethoscopes.

Hitherto Stethoscopes have been made in various ways, but have universally lacked certain qualities which they could possess to great advantage. Foremost among these qualities which the ordinary stethoscope has lacked is sensitiveness. The heart is like a pump, but its operations are on a comparatively small scale, and are furthermore in- Sula-ted from observation by the surrounding tissues, so that only an er of abnormal c delicacy is capable of hearing enough to derive all. the information which might derived.

It is the purpose of this invention to so transmit thesounds, or inother words, to'

provide such a stethoscope, that a person of normal hearing may get practically all the information which is capable of being ob tained by the use of this method of obser-' vation. v v

For this purpose the invention consists in an improved stethoscope making use oil a special telephonic transmitter, receiver and ear tubes. I

In the drawings z- Figure 1 is a view showing the parts and general arrangement of a stethoscope enibodying the principles of this invention. Fig. 2 is a face view or the transmitter. Fig. 3 is a sectional view of the face of the same.

It will be understood that the heart, in beating, contracts and expands, and in so doing produces two or more sources of sound vibrations, or vibrations analogous to e5 sound vibrations. There is, first, the vibration due to the rush of the blood against 7 d through the operating walls, which prouses the usual sound of any rushing liquid,

except to such a slight extent in point of 5c magnitude as to be virtually inaudible. Be sides this there is the effect of a tap duo the ther sudden muscular contraction and Thi a matter of much 'gy than the actual 561 gish or low in pitch to be audible as sound,- or to be transmitted through the air by the phenomenon of radiant or wave energy, as sound is actually. transmitted. In other words, the tap is more in the nature of those vibrations which are too slow, or in other words toofew in number or frequency to be audible to the human ear, or to carry their energyat all through the air by a wave action. in carrying out the present invention particular care is taken to obtain the full efiect of both of these sources of sound or energy".

I employ a very sensitive transmitter known as the dictograph transmitter, and familiarly employed in ordinary secretand detective service under this name. A transmitter of this'type is disclosed in patent to Turner at (47., Ne. 84:4,635. This-patent, however, merely shows the general 'telephonic features oi? this transun'ster as disfeatures more particutinguished from its larly related to present purpose of use.

1 provide a casing 1 having a compara tively sharp l'lill portion 2 which can be pressed against the shin over the heart so as to primarily inalie an air tight joint around this annular rim. This riin furthermore so stretches the skin into a kind of membrane or drumhead to ".nation 3, as to render the skin capable of vibratingsomewhat like a drumhead by virtue of the tap transmitted from the heart; This casing furthermore has a cavity d which is very shallow and of a form which will closely follow the curva ture given to the skin, but without actually touching the latter. In this way there is an air pocket formed which is comparatively large area, but small capacity. ,The result is that slight movements of the skin result in a comparatively large increase in pressure of the air in the cavityfa-s distinguished from avery sinall increase of pressure'which would be the case if the cavity were not so small in its capacity. It must be borne in mind that these slow movements or vibrations are not like sound vibrations in the sense that they can be carried along by indi-,

stretched condition of the skin and the exif it was theactual pansive area and small capacity of the air cavity employed, all of which conditions tend to produce an ultimate movement among the carbon halls of the transmitter which is about proportionate to the intensity of the heart beat. This is of course the result desired. By it the energy of the heart can be plainly heard in its contractions and expansions, and on account of the magnificatioirof sensitiveness the sound is similar to the sound of heavy pumping machinery in which, on account of the large size, there is a dull heavy sound by which a trained ear can tell much about the operation. The same thing is true of the heart with this stethoscope. I am aware that the actual sound heard is not really the sound of the heart, but merely a rubbing movement be tween ,very small carbon balls which is caused by movements of the heart. But the actual sound received is significant and shows the operations of the heart as well as sound of the heart. Of course, in addition tothis there is the actual sound of the rushing blood which is trans mitted to some degree on account of the sensiti'veness of the dictograph transmitter,

The receiver/5 and stethoscope ear pieces 6 and battery 7 present no novel features. As a part of thestethoscope transmitter, however, I have provided a regulating resistance device 8 since it is found in practice that only certain current strengths give thoroughly satisfactory results, so delicate is the operation of this device on account of the great difficulty of the work to 0 be performed.

After the instrument has been properly ible of being heard by a plurality of persons simultaneously, through separate receivers and stethoscope ear pieces. Thus, in the clinic where a patient is receiving anoperation', and where it has hitherto been impos sible for all or even any of the students to use the stethoscope, it is now possible by the present invention to have the whole class share in the full benefits of the operation throughout. Obviously, this result could not be had by any prior art devices because the 'patients condition changes, from moment to moment, and even if the students listened by turns at a single stethoscope, each would get a different result, and each result would be difierentfrom the one received by the instructor or operating physician. For the use of such. clinics he switch. 8 is particularly desirable, since it permits an adjustment of sensitiveness suitable to the number of receivers used.

What I claim is 1. A telephonic stethoscope comprising a transmitter having in combination with its diaphragm and electrode, a mouth-piece having a shallow cavity of relatively large area in the face thereof which is adapted to be placed against a portion of the body of the patient.

' 2. A telephonic stethoscope comprising a transmitter having in combination with its diaphragm and electrode, a mouth-piece consisting of a disk having a shallow saucer shaped cavity of relatively large area in the face thereof adapted to fit against a portion of ,the body of the patient, and a passage wa leading from said cavity to the diaphragm exposing the latter to the variations of air'pressure in said cavity.

Signed at Jamaica, in the county of Queens and State of New York, this 6th day of September, A. D. 1912.

KELLEY M. TURNER.

Witnesses:

EDGAR Lows, E. DOUGLAS 1m GRUcHY.

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